Hair Loss: Common Causes, What Is Temporary and When to Be Seen

What it involves

MedlinePlus calls partial or complete loss of hair alopecia. It says hair loss usually develops gradually and may be patchy or all over. Normally you lose roughly 50 to 200 hairs from your head every day, and the scalp holds about 100,000 hairs, so a few strands in the drain are not a sign of a problem by themselves.

Who this is for

• Adults who notice thinning, a widening part, or bald patches
• Patients who are shedding more hair after an illness, surgery, childbirth, or a big life stress
• Patients with a thyroid problem, anemia, or an autoimmune condition who are losing hair
• Patients unsure whether the hair loss is temporary or needs treatment

What to expect

• Questions about the pattern of hair loss, how fast it started, and whether family members have it
• Questions about hair care, stress, diet, recent illnesses, surgery, and medicines
• A look at the hair and scalp, which MedlinePlus says is usually enough to find the cause
• A plan that may include blood tests, a change in medicines, or a referral to a skin specialist

Pattern hair loss

MedlinePlus says both men and women tend to lose hair thickness and amount as they age, and that this type of hair loss is not usually caused by a disease. It is related to aging, heredity, and changes in the hormone testosterone. Inherited or pattern baldness affects many more men than women, can begin any time after puberty, and about 80% of men show signs of male pattern baldness during their lifetime.

Shedding after stress or illness

MedlinePlus explains that physical or emotional stress may cause one half to three quarters of scalp hair to shed, a type called telogen effluvium. Hair tends to come out in handfuls when you shampoo or comb it, and you may not notice for weeks to months after the cause. Shedding decreases over 6 to 8 months, and it is usually temporary. MedlinePlus lists these causes:

• A high fever or severe infection
• Childbirth, major surgery, major illness, or sudden blood loss
• Severe emotional stress
• Crash diets, especially those without enough protein
• Medicines including retinoids, birth control pills, beta-blockers, calcium channel blockers, certain antidepressants, and NSAIDs

Other causes

MedlinePlus lists several causes that follow an unusual pattern: alopecia areata, anemia, autoimmune conditions such as lupus, hormone changes, thyroid diseases, ringworm of the scalp, and bacterial scalp infections. Hairstyles that pull on the follicles, continual hair pulling or scalp rubbing, and excessive shampooing and blow-drying are on the list too. The thyroid care page explains how thyroid problems are followed, and the anemia and low iron guide covers the other common medical cause. Skin and hair problems sometimes appear together, and the acne guide covers the hormone-related breakouts that MedlinePlus says a provider may treat differently.

Alopecia areata

The NIAMS says alopecia areata happens when the immune system attacks hair follicles. Hair typically falls out in small, round patches about the size of a quarter, most people who get it are in their teens, twenties, or thirties, and most are healthy with no other symptoms. There is no cure, but the NIAMS says there are treatments that help hair grow back more quickly, and in most cases the hair regrows, though later episodes can occur. It is more common in people with thyroid disease, psoriasis, or vitiligo.

Signs you should be seen

MedlinePlus says to contact your provider if you have any of these:

• Hair loss in an unusual pattern, or rapid hair loss, or hair loss at an early age such as the teens or twenties
• Pain or itching with the hair loss, or red, scaly, or otherwise abnormal skin on the scalp
• Bald spots in the beard or eyebrows
• Acne, facial hair, or an abnormal menstrual cycle, or male pattern baldness in a woman
• Weight gain, muscle weakness, intolerance to cold, or fatigue
• Areas of infection on the scalp

What a visit involves

MedlinePlus says a careful history and an exam of the hair and scalp are usually enough to diagnose the cause. Your provider asks about the pattern, how you care for your hair, your stress and diet, and recent illnesses. Blood tests, a microscopic exam of a plucked hair, or a scalp skin biopsy are rarely needed, and the last two would be arranged through a referral. The thyroid blood tests guide and the vitamin D and B12 blood tests guide explain two blood tests that may come up.

Treatment depends on the cause

MedlinePlus says hair loss from illness, radiation, or medicines needs no treatment because hair usually grows back once the cause ends, and loss from menopause or childbirth often goes away after 6 months to 2 years. Scalp ringworm is treated with an antifungal shampoo and oral medicine, a vitamin deficiency with a supplement, and for pattern loss a provider may advise a scalp solution such as minoxidil. A skin problem on the scalp may overlap with the skin conditions evaluation. Never stop a prescribed medicine on your own.

Sources

• MedlinePlus — Hair loss
• NIAMS — Overview of Alopecia Areata