Hitting a point between the middle third and upper third of the line joining the angle of the mouth to the zygomatic process gives rise to only a contraction of the muscles of the mouth and nose.

The Chvostek sign () is a clinical sign of existing nerve hyperexcitability (tetany) seen in hypocalcemia. It refers to an abnormal reaction to the stimulation of the facial nerve. When the facial nerve is tapped in front of tragus the facial muscles on the same side of the face will contract momentarily (typically a twitch of the nose or lips) because of hypocalcemia (i.e. from hypoparathyroidism, pseudohypoparathyroidism, hypovitaminosis D) with resultant hyperexcitability of nerves. Though classically described in hypocalcemia, this sign may also be encountered in respiratory alkalosis, such as that seen in hyperventilation, which causes decreased serum Ca with a normal calcium level due to a shift of Ca from the blood to albumin which has become more negative in the alkalotic state.

The Trousseau sign of latent tetany is also often used to detect early tetany.

Trousseau sign of latent tetany is a medical sign observed in patients with low calcium. From 1 to 4 percent of normal patients will test positive for Trousseau's sign of latent tetany. This sign may be positive before other manifestations of hypocalcemia such as hyperreflexia and tetany, as such it is generally believed to be more sensitive (94%) than the Chvostek sign (29%) for hypocalcemia.

To elicit the sign, a blood pressure cuff is placed around the arm and inflated to a pressure greater than the systolic blood pressure and held in place for 3 minutes. This will occlude the brachial artery. In the absence of blood flow, the patient's hypocalcemia and subsequent neuromuscular irritability will induce spasm of the muscles of the hand and forearm. The wrist and metacarpophalangeal joints flex, the DIP and PIP joints extend, and the fingers adduct. The sign is also known as main d'accoucheur (French for ""hand of the obstetrician"") because it supposedly resembles the position of an obstetrician's hand in delivering a baby.

The sign is named after French physician Armand Trousseau who described the phenomenon in 1861. It is distinct from the Trousseau sign of malignancy.

French Professor Armand Trousseau (1801-1867) devised the trick (now known as the Trousseau sign of latent tetany) of occluding the brachial artery by squeezing, to trigger cramps in the fingers. Also, tetany can be demonstrated by tapping anterior to the ear, at the emergence of the facial nerve. A resultant twitch of the nose or lips suggests low calcium levels. This is now known as the Chvostek sign.

Tetany is characterized by contraction of distal muscles of the hands (carpal spasm with extension of interphalangeal joints and adduction and flexion of the metacarpophalangeal joints) and feet (pedal spasm) and is associated with tingling around the mouth and distally in the limbs.

EMG studies reveal single or often grouped motor unit discharges at low discharge frequency during tetany episodes.

Tetany or tetany seizure is a medical sign consisting of the involuntary contraction of muscles, which may be caused by disease or other conditions that increase the action potential frequency of muscle cells or the nerves that innervate them. Muscle cramps which are caused by the disease tetanus are not classified as tetany; rather, they are due to a lack of inhibition to the neurons that supply muscles.

The Sign of Hertoghe or Queen Anne's sign is a thinning or loss of the outer third of the eyebrows, and is a classical sign of hypothyroidism or dermatitis atopica, but it can also be detected in lepromatous leprosy. The sign is named after Eugene Hertoghe of Antwerp, a pioneer in thyroid function research.

The association with Anne of Denmark is based on portraiture, although history does not suggest that she suffered an underactive thyroid. The eponym is disputed by some, though it has been suggested that Anne of France, Anne of Brittany, Anne of Austria, Anne Boleyn and Anne of Cleves may all be eliminated as candidates.

Hutchinson's mask is a patient's sensation that the face is covered with a mask or a gauzy network like cobwebs. This medical sign is associated with tabes dorsalis affecting the trigeminal nerve (fifth cranial nerve CN V). It is named in honour of the English physician Sir Jonathan Hutchinson (1828–1913).

Lid lag is the static situation in which the upper eyelid is higher than normal with the globe in downgaze. It is most often a sign of thyroid eye disease, but may also occur with cicatricial changes to the eyelid or congenital ptosis. Lid lag differs from Von Graefe's sign in that the latter is a dynamic process.It can also be the manifestaition of chemosis (swelling (or edema) of the conjunctiva)

Von Graefe's sign is the lagging of the upper eyelid on downward rotation of the eye, indicating exophthalmic goiter (Graves' Disease). It is a dynamic sign, whereas lid lag is a static sign which may also be present in cicatricial eyelid retraction or congenital ptosis.

A pseudo Graefe's sign (pseudo lid lag) shows a similar lag, but is due to aberrant regeneration of fibres of the oculomotor nerve (III) into the elevator of the upper lid. It occurs in paramyotonia congenita.

A pseudo Graefe's sign is most commonly manifested in just one eye but can occasionally be observed in both. The reason only one eye is affected is not yet clear.

The term pseudopseudohypoparathyroidism is used to describe a condition where the individual has the phenotypic appearance of pseudohypoparathyroidism type 1a, but is biochemically normal.

Hutchinson's pupil is a clinical sign in which the pupil on the side of an intracranial mass lesion is dilated and unreactive to light, due to compression of the oculomotor nerve on that side. The sign is named after Sir Jonathan Hutchinson.

These can be due to concussion injury to the brain and is associated with subdural haemorrhage and unconsciousness.

The parasympathetic fibers to the pupil are responsible for pupillary constriction. The fibers pass through the periphery of the oculomotor nerve, and hence are the first to be affected in case of compression of the nerve. In Stage 1, the parasympathetic fibers on the side of injury are irritated, leading to constriction of pupil on that side. In stage 2, the parasympathetic fibers on the side of injury are paralysed, leading to dilatation of pupil. The fibers on the opposite oculomotor nerve are irritated, leading to constriction on opposite side. In stage 3, the parasympathetic fibers on both sides are paralysed - leading to bilateral pupillary dilatation. Pupils become fixed. This could typically indicates a very serious underlying condition.

Chilaiditi syndrome is a rare condition when pain occurs due to transposition of a loop of large intestine (usually transverse colon) in between the diaphragm and the liver, visible on plain abdominal X-ray or chest X-ray.

Normally this causes no symptoms, and this is called Chilaiditi's sign. The sign can be permanently present, or sporadically. This anatomical variant is sometimes mistaken for the more serious condition of having air under the diaphragm (pneumoperitoneum) which is usually an indication of bowel perforation, possibly leading to surgical interventions.

Chilaiditi syndrome refers only to complications in the presence of Chilaiditi's sign. These include abdominal pain, torsion of the bowel (transverse colon volvulus) or shortness of breath.

The condition may be a sign of various disease states, including but not exclusive to the following:

- Cancers

- Lymphoma

- Leukemia

- Infections

- HIV/AIDS

- Tuberculosis

- Mycobacterium avium-intracellulare infection

- Infectious mononucleosis

- Fungal infections (histoplasmosis, coccidioidomycosis)

- Lung abscess

- Infective endocarditis

- Brucellosis

- Pneumocystis pneumonia (most often - in immunocompromised individuals)

- Endocrine disorders

- Menopause

- Premature ovarian failure

- Hyperthyroidism

- Diabetes mellitus (nocturnal hypoglycemia)

- Endocrine tumors (pheochromocytoma, carcinoid)

- Orchiectomy

- Rheumatic disorders

- Takayasu's arteritis

- Temporal arteritis

- Other

- Obstructive sleep apnea

- Gastroesophageal reflux disease

- Chronic fatigue syndrome

- Fibromyalgia

- Granulomatous disease

- Chronic eosinophilic pneumonia

- Lymphoid hyperplasia

- Diabetes insipidus

- Prinzmetal's angina

- Anxiety

- Pregnancy

- Drugs

- Antipyretics (salicylates, acetaminophen)

- Antihypertensives

- Dinitrophenol - a common side effect

- Phenothiazines

- Drug withdrawal: ethanol, benzodiazepines, heroin (and other opiates),

- Over-bundling

- Autonomic over-activity

- IBD (inflammatory bowel disease) - Crohn's disease/ulcerative colitis

Pseudohypoparathyroidism is a condition associated primarily with resistance to the parathyroid hormone. Those with the condition have a low serum calcium and high phosphate, but the parathyroid hormone level (PTH) is appropriately high (due to the low level of calcium in the blood). Its pathogenesis has been linked to dysfunctional G Proteins (in particular, Gs alpha subunit). The condition is extremely rare, with an estimated overall prevalence of 7.2/1,000,000 or approximately 1/140000.

Tinel's sign is a way to detect irritated nerves. It is performed by lightly tapping (percussing) over the nerve to elicit a sensation of tingling or "pins and needles" in the distribution of the nerve. It takes its name from French neurologist Jules Tinel (1879–1952).

For example, in carpal tunnel syndrome where the median nerve is compressed at the wrist, Tinel's sign is often "positive" causing tingling in the thumb, index, middle finger and the radial half of the fourth digit. Tinel's sign is sometimes referred to as "distal tingling on percussion" or DTP. This distal sign of regeneration can be expected during different stage of somatosensory recovery.

Although most frequently associated with carpal tunnel syndrome, Tinel's sign is a generalized term, and can also be positive in tarsal tunnel syndrome, or in ulnar nerve impingement at the wrist (Guyon's canal syndrome), where it affects the other (ulnar) half of the fourth digit and the fifth digit.

A chignon is a temporary swelling left on an infant's head after a ventouse suction cap has been used to deliver him or her. It is not a sign of serious injury and may take as little as two hours or as long as two weeks to disappear.

Night sweats, also known as nocturnal hyperhidrosis, is the occurrence of excessive sweating during sleep. The person may or may not also suffer from excessive perspiration while awake.

One of the most common causes of night sweats in women over 40 is the hormonal changes related to menopause and perimenopause. This is a very common occurrence during the menopausal transition years.

While night sweats might be relatively harmless, it can also be a sign of a serious underlying disease. It is important to distinguish night sweats due to medical causes from those that occur simply because the sleep environment is too warm, either because the bedroom is unusually hot or because there are too many covers on the bed. Night sweats caused by a medical condition or infection can be described as "severe hot flashes occurring at night that can drench sleepwear and sheets, which are not related to the environment". Some of the underlying medical conditions and infections that cause these severe night sweats can be life-threatening and should promptly be investigated by a medical practitioner.

A supernumerary nipple (also known as a third nipple, triple nipple, accessory nipple, polythelia or the related condition: polymastia) is an additional nipple occurring in mammals, including humans. Often mistaken for moles, supernumerary nipples are diagnosed in humans at a rate of approximately 1 in 18 people.

The nipples appear along the two vertical "milk lines," which start in the armpit on each side, run down through the typical nipples and end at the groin. They are classified into eight levels of completeness from a simple patch of hair to a milk-bearing breast in miniature.

"Polythelia" refers to the presence of an additional nipple alone while "polymastia" denotes the much rarer presence of additional mammary glands.

Although usually presenting on the milk line, pseudomamma can appear as far away as the foot.

A possible relationship with mitral valve prolapse has been proposed.

The signs and symptoms of X-linked recessive hypoparathyroidism are characteristic of hypoparathyroidism and its consequent hypocalcemia. They include acute symptoms, like paresthesia, twitching of the hands and feet, unconsciousness, and trouble breathing; and chronic symptoms, including seizures, tiredness, irritability, cardiac insufficiency, abnormal heart rhythms, papilledema, cataracts, calcium deposits in the brain, and loss or brittleness of hair, skin, and nails.

Raccoon eye/eyes (also known in the United Kingdom and Ireland as panda eyes) or periorbital ecchymosis is a sign of basal skull fracture or subgaleal hematoma, a craniotomy that ruptured the meninges, or (rarely) certain cancers. Bilateral hemorrhage occurs when damage at the time of a facial fracture tears the meninges and causes the venous sinuses to bleed into the arachnoid villi and the cranial sinuses. In layman's terms, blood from skull fracture seeps into the soft tissue around the eyes. Raccoon eyes may be accompanied by Battle's sign, an ecchymosis behind the ear. These signs may be the only sign of a skull fracture, as it may not show on an X-ray. They may not appear until up 2–3 days after the injury. It is recommended that the patient not blow their nose, cough vigorously, or strain to prevent further tearing of the meninges.

Raccoon eyes may be bilateral or unilateral. If bilateral, it is highly suggestive of basilar skull fracture, with a positive predictive value of 85%. They are most often associated with fractures of the anterior cranial fossa.

Raccoon eyes may also be a sign of disseminated neuroblastoma or of amyloidosis (multiple myeloma).

Depending on cause, raccoon eyes always require urgent consultation and management, that is surgical (facial fracture or post-craniotomy) or medical (neuroblastoma or amyloidosis).

In medicine, enophthalmia describes eyes that are abnormally sunken into their sockets. This condition usually affects elderly persons. Surgery can be done to correct it. Bilateral progressive enophthalmos may be the presenting sign of metastatic breast carcinoma even when local symptoms in the breast are absent.

The exact cause is not always known, but it may occur in patients with a long and mobile colon (dolichocolon), chronic lung disease such as emphysema, or liver problems such as cirrhosis and ascites. Chilaiditi's sign is generally not associated with symptoms, and is most commonly an incidental finding in normal individuals.

Absence or laxity of the ligament suspending the transverse colon or of the falciform ligament are also thought to contribute to the condition. It can also be associated with relative atrophy of the medial segment of the left lobe of the liver. In this case, the gallbladder position is often anomalous as well – it is often located anterior to the liver, rather than posterior.

Parinaud's Syndrome is a cluster of abnormalities of eye movement and pupil dysfunction, characterized by:

1. Paralysis of upgaze: Downward gaze is usually preserved. This vertical palsy is supranuclear, so doll's head maneuver should elevate the eyes, but eventually all upward gaze mechanisms fail.

2. Pseudo-Argyll Robertson pupils: Accommodative paresis ensues, and pupils become mid-dilated and show light-near dissociation.

3. Convergence-Retraction nystagmus: Attempts at upward gaze often produce this phenomenon. On fast up-gaze, the eyes pull in and the globes retract. The easiest way to bring out this reaction is to ask the patient to follow down-going stripes on an optokinetic drum.

4. Eyelid retraction (Collier's sign)

5. Conjugate down gaze in the primary position: "setting-sun sign". Neurosurgeons see this sign most commonly in patients with failed hydrocephalus shunts.

It is also commonly associated with bilateral papilledema. It has less commonly been associated with spasm of accommodation on attempted upward gaze, pseudoabducens palsy (also known as thalamic esotropia) or slower movements of the abducting eye than the adducting eye during horizontal saccades, see-saw nystagmus and associated ocular motility deficits including skew deviation, oculomotor nerve palsy, trochlear nerve palsy and internuclear ophthalmoplegia.

Changes in muscle performance can be broadly described as the upper motor neuron syndrome. These changes vary depending on the site and the extent of the lesion, and may include:

- Muscle weakness. A pattern of weakness in the extensors (upper limbs) or flexors (lower limbs), is known as 'pyramidal weakness'

- Decreased control of active movement, particularly slowness

- Spasticity, a velocity-dependent change in muscle tone

- Clasp-knife response where initial higher resistance to movement is followed by a lesser resistance

- Babinski sign is present, where the big toe is raised (extended) rather than curled downwards (flexed) upon appropriate stimulation of the sole of the foot. The presence of the Babinski sign is an abnormal response in adulthood. Normally, during the plantar reflex, it causes plantar flexion and the adduction of the toes. In Babinski's sign, there is dorsiflexion of the big toe and abduction of the other toes. Physiologically, it is normally present in infants from birth to 12 months. The presence of the Babinski sign after 12 months is the sign of a non-specific upper motor neuron lesion.

- Increased deep tendon reflex (DTR)

- Pronator drift