Cause | Common Features* | Tests |
---|---|---|
Hair loss over the entire scalp | ||
Male-pattern hair loss (androgenetic alopecia) | Often a family history | A doctor's examination |
Female-pattern hair loss (androgenetic alopecia) | Often a family history Sometimes occurring during menopause Menopause Menopause is the permanent end of menstrual periods, ovulation, and fertility. For up to several years before and just after menopause, estrogen levels fluctuate widely, periods become irregular... read more Sometimes in women with masculine characteristics (virilization), a history of using anabolic steroids such as dihydrotestosterone, or a tumor that produces male hormones | A doctor's examination Sometimes measurement of hormones: thyroid hormones, testosterone, DHEAS, FSH, and LH |
Drugs and toxins | A history of using a specific drug such as certain chemotherapy drugs, anticoagulants, retinoids, oral contraceptives, ACE inhibitors, beta-blockers, lithium, antithyroid drugs, anticonvulsants, high doses of vitamin A, or of being exposed to metals such as thallium and arsenic | A doctor's examination Sometimes blood tests to check for exposure to toxins or heavy metals |
Stress (psychologic or physical) causing telogen effluvium | Severe psychologic stress Recent weight loss, surgery, severe illness with a fever, or delivery of a baby | A doctor's examination Sometimes blood tests to check for anemia Overview of Anemia Anemia is a condition in which the number of red blood cells is low. Red blood cells contain hemoglobin, a protein that enables them to carry oxygen from the lungs and deliver it to all parts... read more and iron deficiency Iron Deficiency Iron deficiency is a common cause of anemia, a condition in which the number of red blood cells is low. Iron deficiency usually results from loss of blood in adults (including bleeding from... read more and to evaluate thyroid function Thyroid function blood tests The thyroid is a small gland, measuring about 2 inches (5 centimeters) across, that is located just under the skin in the neck. The two halves (lobes) of the gland are connected in the middle... read more |
Thyroid disorders | With hyperthyroidism Hyperthyroidism Hyperthyroidism is overactivity of the thyroid gland that leads to high levels of thyroid hormones and speeding up of vital body functions. Graves disease is the most common cause of hyperthyroidism... read more (an overactive thyroid gland), difficulty tolerating heat, sweating, weight loss, bulging eyes, shakiness (tremor), restlessness, and an enlarged thyroid gland (goiter) With hypothyroidism Hypothyroidism Hypothyroidism is underactivity of the thyroid gland that leads to inadequate production of thyroid hormones and a slowing of vital body functions. Facial expressions become dull, the voice... read more (an underactive thyroid gland), difficulty tolerating cold, weight gain, coarse and thick skin, and sluggishness | A doctor's examination Blood tests that evaluate thyroid function |
Nutritional disorders, such as vitamin A excess Vitamin A Excess Vitamin A excess (toxicity) can be sudden (acute), usually due to accidental ingestion by children, or chronic. Consuming too much vitamin A causes hair loss, cracked lips, dry skin, weakened... read more or a deficiency of iron Iron Deficiency Iron deficiency is a common cause of anemia, a condition in which the number of red blood cells is low. Iron deficiency usually results from loss of blood in adults (including bleeding from... read more or zinc Zinc Deficiency Zinc deficiency can result from many conditions, including diabetes mellitus, alcohol use disorder, and use of diuretics. People lose their appetite and hair and may feel sluggish and lose their... read more | Symptoms of the specific nutritional disorder | A doctor's examination Sometimes blood tests to check for nutritional disorders |
Typically patchy hair loss, but sometimes loss of all scalp hair (alopecia totalis) Sometimes loss of all body and scalp hair (alopecia universalis) | A doctor’s examination† | |
Hair loss only in a specific area of the scalp | ||
Alopecia areata | Round patches of hair loss with short broken hairs (resembling exclamation points) around the edges of the patches Sometimes a burning sensation or itching Sometimes loss of hair from the side and back edges of the scalp (ophiasis) or central hair loss, with sparing of the hairs at the margin of the scalp (sisaipho) | A doctor’s examination† |
Cutaneous lupus erythematosus | Scattered patches of hair loss Sometimes a rash on the scalp that tends to be red, raised, and scaly Sometimes areas of scarring Sometimes itching | A doctor's examination Blood tests to check for lupus Diagnosis Systemic lupus erythematosus is a chronic autoimmune inflammatory connective tissue disorder that can involve joints, kidneys, skin, mucous membranes, and blood vessel walls. Problems in the... read more Biopsy of the scalp |
Central centrifugal cicatricial alopecia | Slowly progressive hair loss and scarring on the top and back of the scalp Possibly caused by the use of hot combs, chemical relaxers, or hair weaves in people who have a genetic predisposition to develop this disorder | A doctor's examination Biopsy of the scalp |
Lichen planopilaris (lichen planus of the scalp) and frontal fibrosing alopecia | Related disorders that cause scattered patches of hair loss and scarring Called frontal fibrosing alopecia when scarring hair loss occurs predominantly along the front of the hairline and the eyebrows | A doctor's examination Biopsy of the scalp |
Burns, injuries, or radiation (for example, from radiation therapy) | A history of burns, radiation therapy, or injury Often scarring | A doctor's examination |
Bald areas sometimes with small black dots (due to hair that has broken off at the scalp surface) or hairs broken just above the scalp surface Round, scaly areas of skin, which can be red or inflamed May cause scarring | A doctor's examination† Examination of plucked hairs under a microscope and/or culture of plucked hairs | |
Traction alopecia | Braids, rollers, or ponytails that are left in too long or pulled too tight May cause scarring | A doctor's examination† |
Typically an asymmetric, bizarre, irregular hair loss pattern Sometimes obsessive-compulsive behavior Affects women 4 times more often than men | A doctor's examination† | |
* Features include symptoms and results of the doctor's examination. Features mentioned are typical but not always present. | ||
† Rarely, biopsy of the scalp is done. | ||
ACE = angiotensin-converting enzyme; DHEAS = dehydroepiandrosterone sulfate; FSH = follicle-stimulating hormone; LH = luteinizing hormone; PCOS = polycystic ovary syndrome. |