Up to 50% of people with PAD may have no symptoms. Symptoms of PAD in the legs and feet are generally divided into 2 categories:

1. Intermittent claudication—pain in muscles when walking or using the affected muscles that is relieved by resting those muscles. This is due to the unmet oxygen demand in muscles with use in the setting of inadequate blood flow.

2. Critical limb ischemia, consisting of:

Medical signs of PAD in the legs, due to inadequate perfusion, include:

- Noticeable change in color – blueness, or in temperature (coolness) when compared to the other limb.

- Buerger's test can check for pallor on elevation of limb and redness (rubor) on a change to a sitting position, in an assessment of arterial sufficiency.

- Diminished hair and nail growth on affected limb and digits

PAD in other parts of the body depends on the organ affected. Renal artery stenosis can cause renovascular hypertension.

Carotid artery disease can cause strokes and transient ischemic attacks.

Peripheral artery disease (PAD) is a narrowing of the arteries other than those that supply the heart or the brain. When narrowing occurs in the heart, it is called coronary artery disease, while, in the brain, it is called cerebrovascular disease. Peripheral artery disease most commonly affects the legs, but other arteries may also be involved. The classic symptom is leg pain when walking which resolves with rest, known as intermittent claudication. Other symptoms including skin ulcers, bluish skin, cold skin, or poor nail and hair growth may occur in the affected leg. Complications may include an infection or tissue death which may require amputation; coronary artery disease, or stroke. Up to 50% of cases of PAD are without symptoms.

The main risk factor is cigarette smoking. Other risk factors include diabetes, high blood pressure, and high blood cholesterol. The underlying mechanism is usually atherosclerosis. Other causes include artery spasm. PAD is typically diagnosed by finding an ankle-brachial index (ABI) less than 0.90, which is the systolic blood pressure at the ankle divided by the systolic blood pressure of the arm. Duplex ultrasonography and angiography may also be used. Angiography is more accurate and allows for treatment at the same time; however, it is associated with greater risks.

It is unclear if screening for disease is useful as it has not been properly studied. In those with intermittent claudication from PAD, stopping smoking and supervised exercise therapy improves outcomes. Medications, including statins, ACE inhibitors, and cilostazol also may help. Aspirin does not appear to help those with mild disease but is usually recommended in those with more significant disease. Anticoagulants such as warfarin are not typically of benefit. Procedures used to treat the disease include bypass grafting, angioplasty, and atherectomy.

In 2015 about 155 million people had PAD worldwide. In the developed world it affects about 5.3% of 45 to 50 years olds and 18.6% of 85- to 90-year-olds. In the developing world it affects 4.6% of people between the ages of 45 to 50 and 15% of people between the ages of 85 to 90. In the developed world PAD is equally common among men and women while in the developing world women are more commonly affected. In 2015 PAD resulted in about 52,500 deaths up from 16,000 deaths in 1990.

Cardiac ischemia may be asymptomatic or may cause chest pain, known as angina pectoris. It occurs when the heart muscle, or myocardium, receives insufficient blood flow. This most frequently results from atherosclerosis, which is the long-term accumulation of cholesterol-rich plaques in the coronary arteries. Ischemic heart disease is the most common cause of death in most Western countries and a major cause of hospital admissions.

Reduced blood flow to the skin layers may result in mottling or uneven, patchy discoloration of the skin

Arterial insufficiency ulcers (also known as Ischemic ulcers or Ischemic wounds) are mostly located on the lateral surface of the ankle or the distal digits. They are commonly caused by peripheral artery disease (PAD).

The ulcer has punched-out appearance. It is intensely painful. It has gray or yellow fibrotic base and undermining skin margins. Pulses are not palpable. Associated skin changes may be observed, such as thin shiny skin and absence of hair. They are most common on distal ends of limbs. A special type of ischemic ulcer developing in duodenum after severe burns is called Curling's ulcer.

A diabetic foot is a foot that exhibits any pathology that results directly from diabetes mellitus or any long-term (or "chronic") complication of diabetes mellitus. Presence of several characteristic diabetic foot pathologies such as infection, diabetic foot ulcer and neuropathic osteoarthropathy is called diabetic foot syndrome.

Due to the peripheral nerve dysfunction associated with diabetes (diabetic neuropathy), patients have a reduced ability to feel pain. This means that minor injuries may remain undiscovered for a long while. People with diabetes are also at risk of developing a diabetic foot ulcer. Research estimates that the lifetime incidence of foot ulcers within the diabetic community is around 15% and may become as high as 25%.

In diabetes, peripheral nerve dysfunction can be combined with peripheral artery disease (PAD) causing poor blood circulation to the extremities (diabetic angiopathy). Around half of patients with a diabetic foot ulcer have co-existing PAD.

Where wounds take a long time to heal, infection may set in and lower limb amputation may be necessary. Foot infection is the most common cause of non-traumatic amputation in people with diabetes.

The presentation of amyloidosis is broad and depends on the site of amyloid accumulation. The kidney and heart are the most common organs involved.

Amyloid deposition in the kidneys can cause nephrotic syndrome, which results from a reduction in the kidney's ability to filter and hold on to proteins. The nephrotic syndrome occurs with or without elevations in creatinine and blood urea concentration, two biochemical markers of kidney injury. In AA amyloidosis, the kidneys are involved in 91–96% of people, symptoms ranging from protein in the urine to nephrotic syndrome and rarely renal insufficiency.

Amyloid deposition in the heart can cause both diastolic and systolic heart failure. EKG changes may be present, showing low voltage and conduction abnormalities like atrioventricular block or sinus node dysfunction. On echocardiography, the heart shows a restrictive filling pattern, with normal to mildly reduced systolic function. AA amyloidosis usually spares the heart.

People with amyloidosis do not get central nervous system involvement but can develop sensory and autonomic neuropathies. Sensory neuropathy develops in a symmetrical pattern and progresses in a distal to proximal manner. Autonomic neuropathy can present as orthostatic hypotension but may manifest more gradually with nonspecific gastrointestinal symptoms like constipation, nausea, or early satiety.

Accumulation of amyloids in the liver can lead to elevations in serum aminotransferases and alkaline phosphatase, two biomarkers of liver injury, which is seen in about one third of people. Liver enlargement is common. In contrast, spleen enlargement is rare, occurring in 5% of people. Splenic dysfunction, leading to the presence of Howell-Jolly bodies on blood smear, occurs in 24% of people with amyloidosis. Malabsorption is seen in 8.5% of AL amyloidosis and 2.4% of AA amyloidosis. One suggested mechanism for the observed malabsorption is that amyloid deposits in the tips of intestinal villi (fingerlike projections that increase the intestinal area available for absorption of food), begin to erode the functionality of the villi, presenting a sprue-like picture.

A rare development is a susceptibility to bleeding with bruising around the eyes, termed "raccoon-eyes," caused by amyloid deposition in the blood vessels and a reduced activity of thrombin and factor X, two clotting proteins that lose their function after binding with amyloid.

Amyloid deposits in tissue and causes enlargement of structures. Twenty percent of people with AL amyloidosis have an enlarged tongue, that can lead to obstructive sleep apnea, difficulty swallowing, and altered taste. Tongue enlargement does not occur in ATTR or AA amyloidosis. Enlarged shoulders, "shoulder pad sign," results from amyloid deposition in synovial space. Deposition of amyloid in the throat can cause hoarseness. Aβ2MG amyloidosis (Hemodialysis associated amyloidosis) likes to deposit in synovial tissue, causing chronic synovitis, which can lead to repeated carpal tunnel syndrome.

Both the thyroid and adrenal gland can be infiltrated. It is estimated that 10–20% of individuals with amyloidosis have hypothyroidism. Adrenal infiltration may be harder to appreciate given that its symptoms of orthostatic hypotension and low blood sodium concentration may be attributed to autonomic neuropathy and heart failure.

"Amyloid deposits occur in the pancreas of patients with diabetes mellitus, although it is not known if this is functionally important. The major component of pancreatic amyloid is a 37-amino acid residue peptide known as islet amyloid polypeptide or 'amylin.' This is stored with insulin in secretory granules in B cells and is co secreted with insulin." (Rang and Dale's Pharmacology, 2015.)

Symptoms include: pain on weight bearing, frequently after only a short time. The nature of the pain varies widely among individuals. Some people experience shooting pain affecting the contiguous halves of two toes. Others describe a feeling like having a pebble in their shoe or walking on razor blades. Burning, numbness, and paresthesia may also be experienced. The symptoms progress over time, often beginning as a tingling sensation in the ball of the foot.

Morton's neuroma lesions have been found using MRI in patients without symptoms.

Amyloidosis is a group of diseases in which abnormal protein, known as amyloid fibrils, builds up in tissue. Symptoms depend on the type and are often variable. They may include diarrhea, weight loss, feeling tired, enlargement of the tongue, bleeding, numbness, feeling faint with standing, swelling of the legs, or enlargement of the spleen.

There are about 30 different types of amyloidosis, each due to a specific protein misfolding. Some are genetic while others are acquired. They are grouped into localized and systemic forms. The four most common types of systemic disease are light chain (AL), inflammation (AA), dialysis (AβM), and hereditary and old age (ATTR).

Diagnosis may be suspected when protein is found in the urine, organ enlargement is present, or problems are found with multiple peripheral nerves and it is unclear why. Diagnosis is confirmed by tissue biopsy. Due to the variable presentation, a diagnosis can often take some time to reach.

Treatment is geared towards decreasing the amount of the involved protein. This may sometimes be achieved by determining and treating the underlying cause. AL amyloidosis occurs in about 3–13 per million people per year and AA amyloidosis in about 2 per million people per year. The usual age of onset of these two types is 55 to 60 years old. Without treatment, life expectancy is between six months and four years. In the developed world about 1 per 1,000 people die from amyloidosis. Amyloidosis has been described since at least 1639.

People with CTS experience numbness, tingling, or burning sensations in the thumb and fingers, in particular the index and middle fingers and radial half of the ring finger, because these receive their sensory and motor function (muscle control) from the median nerve. Ache and discomfort can possibly be felt more proximally in the forearm or even the upper arm. Less-specific symptoms may include pain in the wrists or hands, loss of grip strength, and loss of manual dexterity.

Some suggest that median nerve symptoms can arise from compression at the level of the thoracic outlet or the area where the median nerve passes between the two heads of the pronator teres in the forearm, although this is debated.

Numbness and paresthesias in the median nerve distribution are the hallmark neuropathic symptoms (NS) of carpal tunnel entrapment syndrome. Weakness and atrophy of the thumb muscles may occur if the condition remains untreated, because the muscles are not receiving sufficient nerve stimulation. Discomfort is usually worse at night and in the morning.

Many signs are associated with PPID, but only a subset of these are displayed in any single horse. Some horses may present with chronic laminitis without other overt signs of the disease.

- Hypertrichosis (hirsutisim) produces a long, thick, wavy coat that often has delayed shedding or fails to shed completely, and may lighten in color. Hirsutism has been suggested to be pathognomonic for PPID, with up to 95% of horses having PPID.

- Laminitis

- Increased drinking and increased urination

- Pot-bellied appearance

- Weight loss

- Redistribution of fat, leading to bulging supraorbital fat pad, a "cresty" neck, and fat over the tail head or in the sheath of males

- Lethargy

- Behavioral changes, often an increased docility

- Muscle wasting, especially along the top line

- Increased sweating, or less commonly, decreased sweating

- Increased appetite

- Decreased sensitivity to pain

- Recurrent infections due to immune impairment

- Rarely neurologic signs such as narcolepsy, blindness, or seizures

- Suspensary ligament degeneration

Pituitary pars intermedia dysfunction (PPID), or equine Cushing's disease, is an endocrine disease affecting the pituitary gland of horses. It is most commonly seen in older animals, and is classically associated with the formation of a long, wavy coat (hirsutism) and chronic laminitis.

The main differential diagnosis of heel pad syndrome is plantar fasciitis. In heel pad syndrome all parts of the heel are tender while in plantar fasciitis typically only the part of the heel closer to the toes is sore.

Heel pad syndrome, also known as heel fat pad syndrome, heel pad atrophy and heel fat pad atrophy, is a pain that occurs in the center of the heel. It is typically due to atrophy of the fat pad which makes up the heel. Risk factors include obesity. Other conditions with similar symptoms include plantar fasciitis. Treatment includes rest, pain medication, and heel cups. It becomes more common with age.

Treatment of diabetic foot can be challenging and prolonged; it may include orthopaedic appliances, antimicrobial drugs and topical dressings.

Most diabetic foot infections (DFIs) require treatment with systemic antibiotics. The choice of the initial antibiotic treatment depends on several factors such as the severity of the infection, whether the patient has received another antibiotic treatment for it, or whether the infection has been caused by a micro-organism that is known to be resistant to usual antibiotics (e.g. MRSA). The objective of antibiotic therapy is to stop the infection and ensure it does not spread.

It is unclear whether any particular antibiotic is better than any other for curing infection or avoiding amputation. One trial suggested that ertapenem with or without vancomycin is more effective than tigecycline for resolving DFIs. It is also generally unclear whether different antibiotics are associated with more or fewer adverse effects.

It is recommended however that the antibiotics used for treatment of diabetic foot ulcers should be used after deep tissue culture of the wound. Tissue culture and not pus swab culture should be done. Antibiotics should be used at correct doses in order to prevent the emergence of drug resistance.

Morton's neuroma (also known as Morton neuroma, Morton's metatarsalgia, Intermetatarsal neuroma and Intermetatarsal space neuroma.) is a benign neuroma of an intermetatarsal plantar nerve, most commonly of the second and third intermetatarsal spaces (between 2nd−3rd and 3rd−4th metatarsal heads), which results in the entrapment of the affected nerve. The main symptoms are pain and/or numbness, sometimes relieved by removing narrow or high-heeled footwear. Sometimes symptoms are relieved by wearing non-constricting footwear.

Some sources claim that entrapment of the plantar nerve because of compression between the metatarsal heads, as originally proposed by Morton, is highly unlikely, because the plantar nerve is on the plantar side of the transverse metatarsal ligament and thus does not come in contact with the metatarsal heads. It is more likely that the transverse metatarsal ligament is the cause of the entrapment.

Despite the name, the condition was first correctly described by a chiropodist named Durlacher, and although it is labeled a "neuroma", many sources do not consider it a true tumor, but rather a perineural fibroma (fibrous tissue formation around nerve tissue).

Carpal tunnel syndrome (CTS) is a medical condition due to compression of the median nerve as it travels through the wrist at the carpal tunnel. The main symptoms are pain, numbness, and tingling, in the thumb, index finger, middle finger, and the thumb side of the ring fingers. Symptoms typically start gradually and during the night. Pain may extend up the arm. Weak grip strength may occur and after a long period of time the muscles at the base of the thumb may waste away. In more than half of cases both sides are affected.

Risk factors include obesity, repetitive wrist work, pregnancy, and rheumatoid arthritis. There is tentative evidence that hypothyroidism increases the risk. Diabetes mellitus is weakly associated with CTS. The use of birth control pills does not affect the risk. Types of work that are associated include computer work, work with vibrating tools, and work that requires a strong grip. Diagnosis is suspected based on signs, symptoms, and specific physical tests and may be confirmed with electrodiagnostic tests. If muscle wasting at the base of the thumb is present, the diagnosis is likely.

Being physically active can decrease the risk of developing CTS. Symptoms can be improved by wearing a wrist splint or with corticosteroid injections. Taking NSAIDs or gabapentin does not appear to be useful. Surgery to cut the transverse carpal ligament is effective with better results at a year compared to non surgical options. Further splinting after surgery is not needed. Evidence does not support magnet therapy.

About 5% of people in the United States have carpal tunnel syndrome. It usually begins in adulthood and women are more commonly affected than men. Up to 33% of people may improve without specific treatment over approximately a year. Carpal tunnel syndrome was first fully described after World War II.

Superior oblique myokymia is a neurological disorder affecting vision and was named by Hoyt and Keane in 1970.

It is a condition that presents as repeated, brief episodes of movement, shimmering or shaking of the vision of one eye, a feeling of the eye trembling, or vertical/tilted vision. It can present as one or more of these symptoms. Diagnosis is most often made by the elimination of other conditions, disorders or diseases.

Onset usually occurs in adulthood, and the course is benign and is not commonly associated with other disorders.

When plantar fasciitis occurs, the pain is typically sharp and usually unilateral (70% of cases). Heel pain is worsened by bearing weight on the heel after long periods of rest. Individuals with plantar fasciitis often report their symptoms are most intense during their first steps after getting out of bed or after prolonged periods of sitting. Improvement of symptoms is usually seen with continued walking. Rare, but reported symptoms include numbness, tingling, swelling, or radiating pain. Typically there are no fevers or night sweats.

If the plantar fascia continues to be overused in the setting of plantar fasciitis, the plantar fascia can rupture. Typical signs and symptoms of plantar fascia rupture include a clicking or snapping sound, significant local swelling, and acute pain in the sole of the foot.

Obesity is a medical condition in which excess body fat has accumulated to the extent that it may have a negative effect on health. People are generally considered obese when their body mass index (BMI), a measurement obtained by dividing a person's weight by the square of the person's height, is over , with the range defined as overweight. Some East Asian countries use lower values. Obesity increases the likelihood of various diseases and conditions, particularly cardiovascular diseases, type 2 diabetes, obstructive sleep apnea, certain types of cancer, osteoarthritis and depression.

Obesity is most commonly caused by a combination of excessive food intake, lack of physical activity, and genetic susceptibility. A few cases are caused primarily by genes, endocrine disorders, medications, or mental disorder. The view that obese people eat little yet gain weight due to a slow metabolism is not generally supported. On average, obese people have a greater energy expenditure than their normal counterparts due to the energy required to maintain an increased body mass.

Obesity is mostly preventable through a combination of social changes and personal choices. Changes to diet and exercising are the main treatments. Diet quality can be improved by reducing the consumption of energy-dense foods, such as those high in fat and sugars, and by increasing the intake of dietary fiber. Medications may be used, along with a suitable diet, to reduce appetite or decrease fat absorption. If diet, exercise, and medication are not effective, a gastric balloon or surgery may be performed to reduce stomach volume or length of the intestines, leading to feeling full earlier or a reduced ability to absorb nutrients from food.

Obesity is a leading preventable cause of death worldwide, with increasing rates in adults and children. In 2015, 600 million adults (12%) and 100 million children were obese. Obesity is more common in women than men. Authorities view it as one of the most serious public health problems of the 21st century. Obesity is stigmatized in much of the modern world (particularly in the Western world), though it was seen as a symbol of wealth and fertility at other times in history and still is in some parts of the world. In 2013, the American Medical Association classified obesity as a disease.

In 1983, Bringewald postulated that superior oblique myokymia resulted from vascular compression of the trochlear nerve (fourth cranial nerve), which controls the action of the superior oblique muscle in the eye. By 1998, there had been only one reported case of compression of the trochlear nerve by vessels.

More recently, magnetic resonance imaging experiments have shown that neurovascular compression at the root exit zone of the trochlear nerve can result in superior oblique myokymia.

Obesity is a medical condition in which excess body fat has accumulated to the extent that it may have an adverse effect on health. It is defined by body mass index (BMI) and further evaluated in terms of fat distribution via the waist–hip ratio and total cardiovascular risk factors. BMI is closely related to both percentage body fat and total body fat.

In children, a healthy weight varies with age and sex. Obesity in children and adolescents is defined not as an absolute number but in relation to a historical normal group, such that obesity is a BMI greater than the 95th percentile. The reference data on which these percentiles were based date from 1963 to 1994, and thus have not been affected by the recent increases in weight. BMI is defined as the subject's weight divided by the square of their height and is calculated as follows.

BMI is usually expressed in kilograms per square metre, resulting when weight is measured in kilograms and height in metres. To convert from pounds per square inch multiply by .

The most commonly used definitions, established by the World Health Organization (WHO) in 1997 and published in 2000, provide the values listed in the table.

Some modifications to the WHO definitions have been made by particular organizations. The surgical literature breaks down class II and III obesity into further categories whose exact values are still disputed.

- Any BMI ≥ 35 or 40 kg/m is "severe obesity".

- A BMI of ≥ 35 kg/m and experiencing obesity-related health conditions or ≥40–44.9 kg/m is "morbid obesity".

- A BMI of ≥ 45 or 50 kg/m is "super obesity".

As Asian populations develop negative health consequences at a lower BMI than Caucasians, some nations have redefined obesity; Japan have defined obesity as any BMI greater than 25 kg/m while China uses a BMI of greater than 28 kg/m.

Bumblefoot (ulcerative pododermatitis) is a bacterial infection and inflammatory reaction on the feet of birds, rodents, and rabbits. Ulcerative pododermatitis is referred to as "sore hocks" when it affects a rabbit and "bumblefoot" when it affects a bird. The terms "sore hocks" and "bumblefoot" are used interchangeably when describing ulcerative pododermatitis in rodents. The infection can usually be attributed to poor husbandry practices, therefore is much more likely to occur in captive animals than in those in the wild. It is caused by bacteria, namely strains of "Staphylococcus", "Pseudomonas" and "Escherichia coli" "(E. coli)", with "S. aureus" being the most common cause of the infection.

The size of oral mucoceles vary from 1 mm to several centimeters and they usually are slightly transparent with a blue tinge. On palpation, mucoceles may appear fluctuant but can also be firm. Their duration lasts from days to years, and may have recurrent swelling with occasional rupturing of its contents.