Symptoms of heat exhaustion include nausea, dizziness, irritability, headache, thirst, weakness, high body temperature, excessive sweating, and decreased urine output.

One major symptom of a mental breakdown is depression. When someone is depressed they may experience weight loss or gain (often due to changes in appetite), suicidal thoughts, loss of interest in social, family or work life, insomnia or hypersomnia, exhaustion or fatigue and feelings of hopelessness or worthlessness. Another symptom of a breakdown is anxiety, which can produce an increase in blood pressure, dizziness, trembling, or feeling sick to the stomach. Panic attacks are very similar to mental breakdowns, but can also be a symptom in some cases. Difficulty with breathing and extreme fear, alongside rapid heartbeat may occur in those who are experiencing a panic attack. In more severe cases of mental breakdown, a person may experience mood swings, hallucinations, paranoia, and flashbacks. In each of these more severe cases there can be a more serious underlying problem that caused the mental breakdown. Hallucinations may suggest schizophrenia or other disorders involving psychosis, mood swings may suggest bipolar disorder or other mood disorders (or personality disorders such as BPD), and flashbacks may suggest posttraumatic stress disorder. The severity of each of these disorders and symptoms may vary based upon the person and their background.

Common causes of heat exhaustion include:

- Hot, sunny, humid weather

- Physical exertion, especially in hot, humid weather

- Due to impaired thermoregulation, elderly people and infants can get serious heat illness even at rest, if the weather outside is hot and humid, and they are not getting enough cool air.

- Some drugs, such as diuretics, antihistamines, beta-blockers, alcohol, ecstasy, and amphetamines can cause an increase in the risk of heat exhaustion.

Especially during physical exertion, risk factors for heat exhaustion include:

- Wearing dark, padded, or insulated clothing; hats; and/or helmets (for example, football pads or turnout gear)

- Having a higher percentage of body fat

- Dehydration

- Fever

- Some medications, like beta blockers and antipsychotic medicines

Causes of such breakdowns are varied. A 1996 study found that problems with intimate relationships, such as divorce or marital separation, contributed to 24% of nervous breakdowns. Problems at work and school accounted for 17% of cases, and financial problems for 11%. Surveys suggest that in the United States, health problems have decreased in importance as a contributor to nervous breakdowns. Health problems accounted for 28% of nervous breakdowns in 1957, 12% in 1976, and only 5.6% in 1996.

A nervous breakdown is very similar to a panic attack. Stress is a major cause in both cases and they are both temporary. During a nervous breakdown, a person's emotional state of being shifts from an ability to cope with life stresses to a state of being totally overwhelmed to a point that normal functioning is disrupted. Excessive worry, nervousness, fear, anxiety are symptomatic. These states of being are accompanied by a variety of uncomfortable feelings often summarized as bad or sad. If these feelings become so intense they are perceived as life-threatening, the defense system blocks awareness. These mechanisms while protective can also be limiting to successful living. Overwhelming stress, therefore, is causative. Whether that stress is self-created or external requires different approaches and has different implications to the individual.

A nervous breakdown is not limited to any one type of person: anyone can have this breakdown, but if someone is under a lot of stress and has a family background of mental disorders, they can be more likely to have one.

Faintness, dizziness, headache, increased pulse, restlessness, nausea, vomiting, and brief loss of consciousness.

Heat cramps, a type of heat illness, are muscle spasms that result from loss of large amount of salt and water through exercise. Heat cramps are associated with cramping in the abdomen, arms and calves. This can be caused by inadequate consumption of fluids or electrolytes. Frequently, they don't occur until sometime later, especially at night or when relaxing. Heavy sweating causes heat cramps, especially when the water is replaced without also replacing salt or potassium.

Although heat cramps can be quite painful, they usually don't result in permanent damage, though they can be a symptom of heat stroke or heat exhaustion. Heat cramps can indicate a more severe problem in someone with heart disease or if they last for longer than an hour.

In order to prevent them, one may drink electrolyte solutions such as sports drinks during exercise or strenuous work or eat potassium-rich foods like bananas and apples. When heat cramps occur, the affected person should avoid strenuous work and exercise for several hours to allow for recovery.

Muscle weakness, also known as muscle fatigue, (or "lack of strength") refers to the inability to exert force with one's skeletal muscles. Weakness often follows muscle atrophy and a decrease in activity, such as after a long bout of bedrest as a result of an illness. There is also a gradual onset of muscle weakness as a result of sarcopenia - the age-related loss of skeletal muscle.

A test of strength is often used during a diagnosis of a muscular disorder before the etiology can be identified. Such etiology depends on the type of muscle weakness, which can be true or perceived as well as variable topically. True weakness is substantial, while perceived rather is a sensation of having to put more effort to do the same task. On the other hand, various topic locations for muscle weakness are central, neural and peripheral. Central muscle weakness is an overall exhaustion of the whole body, while peripheral weakness is an exhaustion of individual muscles. Neural weakness is somewhere between.

Central nervous system fatigue, or central fatigue, is a form of fatigue that is associated with changes in the synaptic concentration of neurotransmitters within the central nervous system (CNS; including the brain and spinal cord) which affects exercise performance and muscle function and cannot be explained by peripheral factors that affect muscle function. In healthy individuals, central fatigue can occur from prolonged exercise and is associated with neurochemical changes in the brain, primarily involving serotonin (5-HT), noradrenaline, and dopamine. Central fatigue plays an important role in endurance sports and also highlights the importance of proper nutrition in endurance athletes.

Frailty is a common geriatric syndrome that embodies an elevated risk of catastrophic declines in health and function among older adults. Frailty is a condition associated with ageing, and it has been recognized for centuries. As described by Shakespeare in "As You Like It", "the sixth age shifts into the lean and slipper’d pantaloon, with spectacles on nose and pouch on side, his youthful hose well sav’d, a world too wide, for his shrunk shank…". The shrunk shank is a result of loss of muscle with aging. It is also a marker of a more widespread syndrome of frailty, with associated weakness, slowing, decreased energy, lower activity, and, when severe, unintended weight loss.

As a population ages, a central focus of geriatricians and public health practitioners is to understand, and then beneficially intervene on, the factors and processes that put elders at such risk, especially the increased vulnerability to stressors (e.g. extremes of heat and cold, infection, injury, or even changes in medication) that characterizes many older adults.

Starvation is a severe deficiency in caloric energy intake, below the level needed to maintain an organism's life. It is the most extreme form of malnutrition. In humans, prolonged starvation can cause permanent organ damage and eventually, death. The term inanition refers to the symptoms and effects of starvation. Starvation may also be used as a means of torture or execution.

According to the World Health Organization, hunger is the single gravest threat to the world's public health. The WHO also states that malnutrition is by far the biggest contributor to child mortality, present in half of all cases. Undernutrition is a contributory factor in the death of 3.1 million children under five every year. Figures on actual starvation are difficult to come by, but according to the Food and Agriculture Organization, the less severe condition of undernourishment currently affects about 842 million people, or about one in eight (12.5%) people in the world population.

The bloated stomach, as seen in the adjacent picture, represents a form of malnutrition called kwashiorkor which is caused by insufficient protein despite a sufficient caloric intake. Better medicine will prevent the pictured symptoms in which included is weight loss and muscle wasting from further taking form.

Heat syncope is fainting or dizziness as a result of overheating ("syncope" is the medical term for fainting). It is a type of heat illness. The basic symptom of heat syncope is fainting, with or without mental confusion. Heat syncope is caused by peripheral vessel dilation, resulting in diminished blood flow to the heart and dehydration.

Young males are most often affected, though similar symptoms have been reported in females with excessive vaginal discharge or leucorrhea, which is also considered a "vital fluid".

Premature ejaculation and impotence are commonly seen. Other somatic symptoms like weakness, easy fatiguability, palpitations, insomnia, low mood, guilt and anxiety are often present. Males sometimes report a subjective feeling that their penises have shortened. These symptoms are usually associated with an anxious and dysphoric mood state.

The distinguishing characteristics of POIS are:

1. the rapid onset of symptoms after ejaculation;

2. the absence of any local genital reaction; and

3. the presence of an overwhelming systemic reaction.

POIS symptoms, which are called a "POIS attack", can include some combination of the following: cognitive dysfunction, aphasia, severe muscle pain throughout the body, severe fatigue, weakness, and flu-like or allergy-like symptoms, such as sneezing, itchy eyes, and nasal irritation. Additional symptoms include intense discomfort, irritability, anxiety, craving for relief, susceptibility to nervous system stresses (e.g. common cold), depressed mood, and difficulty communicating, remembering words, reading and retaining information, concentrating, and socializing. Affected individuals may also experience intense warmth or cold.

The symptoms begin shortly after or within a half hour of ejaculation.

The symptoms can last for several days, sometimes up to a week.

In some men, the onset of POIS is in puberty, while in others, the onset is in their twenties. POIS that is manifest from the first ejaculations in adolescence is called "primary type"; POIS that starts later in life is called "secondary type".

Many POIS sufferers report lifelong premature ejaculation, with intravaginal ejaculation latency time (IELT) of less than one minute.

A number of heat illnesses exist including:

- Heat stroke - Defined by a body temperature of greater than due to environmental heat exposure with lack of thermoregulation. Symptoms include dry skin, rapid, strong pulse and dizziness.

- Heat exhaustion - Can be a precursor of heatstroke; the symptoms include heavy sweating, rapid breathing and a fast, weak pulse.

- Heat syncope - Fainting or dizziness as a result of overheating.

- Heat edema

- Heat cramps - Muscle pains that happen during heavy exercise in hot weather.

- Heat rash - Skin irritation from excessive sweating.

- Heat tetany - Usually results from short periods of stress in intense heat. Symptoms may include hyperventilation, respiratory problems, numbness or tingling, or muscle spasms.

Causes of hunger are related to poverty. There are inter-related issues causing hunger, which are related to economics and other factors that cause poverty. They include land rights and ownership, diversion of land use to non productive use, increasing emphasis on export oriented agriculture, inefficient agricultural practices, war, famine, drought, over fishing, poor crop yield, etc.

The basic cause of starvation is an imbalance between energy intake and energy expenditure. In other words, the body expends more energy than it takes in. This imbalance can arise from one or more medical conditions or circumstantial situations, which can include:

Medical reasons

- Anorexia nervosa

- Bulimia nervosa

- Eating disorder, not otherwise specified

- Celiac disease

- Coma

- Major depressive disorder

- Diabetes mellitus

- Digestive disease

- Constant vomiting

Circumstantial causes

- Child/ Elder/ Dependent Abuse

- Faminefor any reason, such as political strife and war

- Excessive fasting

- Poverty

The main causes of starvation are as follows:

- Economy; poor people sometimes cannot buy enough foodstuffs and thereby fail to fulfill the caloric demands of the body.

- Food scarcity in the society. This causes a decreased supply of food to the whole of the population, and thus mass starvation may occur.

- Diseases that can cause rapid weight loss either due to the nature of the disease or the inability of the person to either eat or eat enough due to symptoms including fatigue, nausea, and vomiting. The person may also be the host to a parasite such as an intestinal worm which may take a significant amount of the calories ingested by its host. This effect is exacerbated if the human host is already ingesting far less food than is required to meet their daily caloric intake needs.

- Clinical conditions, such as recovering from surgery or burns, etc., in which the person may be too fatigued or incapacitated to eat enough during their period of convalescence.

An early stage of hyperthermia can be "heat exhaustion" (or "heat prostration" or "heat stress"), whose symptoms include heavy sweating, rapid breathing and a fast, weak pulse. If the condition progresses to heat stroke, then hot, dry skin is typical as blood vessels dilate in an attempt to increase heat loss. An inability to cool the body through perspiration may cause the skin to feel dry.

Other signs and symptoms vary. Accompanying dehydration can produce nausea, vomiting, headaches, and low blood pressure and the latter can lead to fainting or dizziness, especially if the standing position is assumed quickly.

In severe heat stroke, there may be confused, hostile, or seemingly intoxicated behavior. Heart rate and respiration rate will increase (tachycardia and tachypnea) as blood pressure drops and the heart attempts to maintain adequate circulation. The decrease in blood pressure can then cause blood vessels to contract reflexively, resulting in a pale or bluish skin color in advanced cases. Young children, in particular, may have seizures. Eventually, organ failure, unconsciousness and death will result.

In humans, hyperthermia is defined as a temperature greater than , depending on the reference used, that occurs without a change in the body's temperature set point.

The normal human body temperature can be as high as in the late afternoon. Hyperthermia requires an elevation from the temperature that would otherwise be expected. Such elevations range from mild to extreme; body temperatures above can be life-threatening.

Postorgasmic illness syndrome (POIS) is a syndrome in which men have severe cognitive and physical symptoms immediately following ejaculation in the absence of a local genital reaction. The symptoms last for up to a week. The cause and prevalence are unknown; it is considered a rare disease.

From 1869, neurasthenia became a "popular" diagnosis, expanding to include such symptoms as weakness, dizziness and fainting, and a common treatment was the rest cure, especially for women, who were the gender primarily diagnosed with this condition at that time. Recent analysis, however, of data from this period gleaned from the Annual Reports of Queen Square Hospital, London, indicates that the diagnosis was more evenly balanced between the sexes than is commonly thought. Virginia Woolf was known to have been forced to have rest cures, which she describes in her book "On Being Ill". Charlotte Perkins Gilman's protagonist in "The Yellow Wallpaper" also suffers under the auspices of rest cure doctors, much as Gilman herself did. Marcel Proust was said to suffer from neurasthenia. To capitalize on this epidemic, the Rexall drug company introduced a medication called 'Americanitis Elixir' which claimed to be a soother for any bouts related to Neurasthenia.

Although many people with a defective AMPD gene are asymptomatic, others may have symptoms such as exercise intolerance, muscle pain, and muscle cramping.

- Fatigue

- MADD lowers aerobic power output, so increased anaerobic power is needed to perform the same amount of work.

- Without myoadenlyate deaminase, heavy activity causes adenosine to be released into the cell or perfused into the surrounding tissues. Fatigue and sedation after heavy exertion can be caused by excess adenosine in the cells which signals muscle fiber to feel fatigued. In the brain, excess adenosine decreases alertness and causes sleepiness. In this way, adenosine may play a role in fatigue from MADD.

- Recovery from over-exertion can be hours, days or even months. In cases of rhabdomyolysis, which is the rapid breakdown of muscle fibers, time to recovery is dependent on duration and intensity of original activity plus any excess activity during the recovery period.

- Muscle pain

- Muscle pain from MADD is not well understood, but is partially due to high levels of lactate. Increased levels of free adenosine temporarily decrease pain, allowing over-exertion without awareness. The over exertion can cause mild to severe cases of rhabdomyolysis, which is painful.

- Adenosine mediates pain through adenosine receptors. MADD causes an increase of free adenosine during heavy activity which may cause exercise-induced muscle pain. Over time, excess free adenosine down-regulates primary A1 adenosine receptors, leading to increased muscle pain. Secondary receptors (A3) increase peripheral inflammation, which also increases pain.

- Muscle cramping

- The cause of cramping is unknown, but may be related to elevated lactate, increased calcium signaling across the sarcoplasmic reticulum caused by membrane instability from reduced levels of ATP, or increased levels of free adenosine.

- Muscle weakness

- Muscle weakness is not a major symptom, though the progressive effects of chronic muscle damage from rhabdomyolysis will eventually cause significant weakness. Similarly, the long-term metabolic effects may result in nerve damage.

The condition was explained as being a result of exhaustion of the central nervous system's energy reserves, which Beard attributed to modern civilization. Physicians in the Beard school of thought associated neurasthenia with the stresses of urbanization and with stress suffered as a result of the increasingly competitive business environment. Typically, it was associated with upper class people and with professionals working in sedentary occupations, but really can apply to anyone who lives within the monetary system.

Freud included a variety of physical symptoms in this category, including fatigue, dyspepsia with flatulence, and indications of intra-cranial pressure and spinal irritation. In common with some other people of the time, he believed this condition to be due to "non-completed coitus" or the non-completion of the higher cultural correlate thereof, or to "infrequency of emissions" or the infrequent practice of the higher cultural correlate thereof. Later, Freud formulated that in cases of coitus interruptus as well as in cases of masturbation, there was "an insufficient libidinal discharge" that had a poisoning effect on the organism, in other words, neurasthenia was the result of (auto-)intoxication. Eventually he separated it from anxiety neurosis, though he believed that a combination of the two conditions existed in many cases.

Signs of laryngeal paralysis include voice change (the dog's bark becomes hoarse-sounding), gagging or coughing (often during or after eating or drinking), exercise intolerance, inspiratory stridor (noisy breathing on inspiration), difficulty breathing, and in severe cases cyanosis or syncope (fainting). Secondary problems may also occur, including aspiration or edema in the lungs, though often the problem remains an upper respiratory problem. Affected dogs are vulnerable to heat stroke and heat exhaustion due to their limited ability to cool themselves down by panting, but the disorder itself can be mistaken for heat stroke.

Signs may occur at any time, but initially owners may only notice that their dog's bark sounds different, that their dog can't run as much as before, or that the dog has trouble in hot weather in unilateral cases because the unaffected side can compensate for the paralysed side. However most unilateral cases will eventually progress to include both sides of the larynx, a more serious problem with symptoms appearing more often.

Signs are usually worse in hot and humid weather, during exercise, during times of stress or excitement, and in obese pets. Acute or late-stage symptoms are usually unmistakable and require immediate emergency treatment.

Sweat is readily visualized by a topical indicator such as iodinated starch (Minor test) or sodium alizarin sulphonate, both of which undergo a dramatic colour change when moistened by sweat. A thermoregulatory sweat test can evaluate the body’s response to a thermal stimulus by inducing sweating through a hot box ⁄ room, thermal blanket or exercise. Failure of the topical indicator to undergo a colour change during thermoregulatory sweat testing indicates hypohidrosis, and further tests may be required to localize the lesion.

Magnetic resonance imaging of the brain and ⁄ or spinal cord is the best modality for evaluation when the lesion is suspected to be localized to the central nervous system.

Skin biopsies are useful when anhidrosis occurs as part of a dermatological disorder. Biopsy results may reveal the sweat gland destruction, necrosis or fibrosis, in addition to the findings of the primary dermatological disorder.

Dhat syndrome (Sanskrit: धातु दोष, IAST: Dhātu doṣa) is a condition found in the cultures of the Indian subcontinent in which male patients report that they suffer from premature ejaculation or impotence, and believe that they are passing semen in their urine. The condition has no known organic cause.

In traditional Hindu spirituality, semen is described as a "vital fluid". The discharge of this "vital fluid", either through sex or masturbation, is associated with marked feelings of anxiety and dysphoria. Often the patient describes the loss of a whitish fluid while passing urine. At other times, marked feelings of guilt associated with what the patient assumes is "excessive" masturbation are noted.

Many doctors view dhat as a folk diagnostic term used in India to refer to anxiety and hypochondriacal concerns associated with the discharge of semen, with discoloration of the urine, and feelings of weakness and exhaustion. Dhat is thought to be a culture-bound syndrome similar to "jiryan" (South-East Asia), "prameha" (Sri Lanka), and "shen-k'uei" (China). Dhat syndrome might be related to other post-orgasmic diseases, such as post-coital tristesse (PCT), postorgasmic illness syndrome (POIS), and sexual headache.

Laryngeal paralysis in animals is a condition in which the nerves and muscles that control the movements of one or both arytenoid cartilages of the larynx cease to function, and instead of opening during inspiration and closing during swallowing, the arytenoids remain stationary in a somewhat neutral position. Specifically, the muscle that causes abduction of the arytenoid cartilage, the cricoarytenoideus dorsalis muscle, ceases to function. This leads to inadequate ventilation during exercise and during thermoregulatory panting as well as incomplete protection of the airway during swallowing.

One of the commonest forms of laryngeal paralysis develops in geriatric medium to large breed dogs, in particular the Labrador retriever, but also some other breeds. This had been traditionally known as idiopathic largyngeal paralysis ("ILP": idiopathic means "of unknown cause"), and was believed to be a result of a condition affecting the nerves of the larynx (bilateral mononeuropathy of the recurrent laryngeal nerves). However investigations into ILP by two groups in Michigan and Tennessee between 2005 - 2013 showed that the condition was not limited to, or specifically a result of, dysfunction of the laryngeal nerves. Instead it was the most visible symptom of a slowly progressing polyneuropathy of old age, which also affected other nerves in the body. This finding, now generally believed correct following further research, has led to the proposed renaming of this type of laryngeal paralysis from "Idiopathic laryngeal paralysis" ("ILP") to "Geriatric onset laryngeal paralysis polyneuropathy" ("GOLPP").

Animals affected by laryngeal paralysis have reduced tolerance for exercise and heat and an increased risk of aspiration pneumonia. The condition is not generally regarded as causing pain, other than physical distress and anxiety caused by any difficulty in breathing or emotional distress from any difficulty with physical movement. Where laryngeal paralysis is related to a general progressive polyneuropathy, as in GOLPP, the nervous system will gradually degenerate causing increasing difficulty in management of the limbs (especially rear limbs), swallowing and breathing, and eventually in most cases euthanasia. Laryngeal paralysis is fairly common in large breed and geriatric dogs, particularly in the Labrador retriever, is rarely found in cats, and can also occur in horses where it is referred to as roaring, roarer's syndrome, or medically as laryngeal hemiplegia or recurrent laryngeal neuropathy (RLN). Laryngeal paralysis can be unilateral or bilateral depending upon dysfunction of one or both arytenoid cartilages.