Hair Loss and Hair Health

Healthy hair is often a reflection of overall health. Hair grows from its roots at an average rate of approximately one centimeter (approximatelhy half an inch) each month. Like your skin—the body's largest organ—your hair depends on adequate nutrition, healthy hormone balance, and good overall health to grow and remain strong.

Because many medical conditions can affect hair growth, it is important to look at the whole person rather than simply treating the hair itself. Hair thinning may be the first sign of an underlying nutritional deficiency, hormonal imbalance, thyroid disorder, iron deficiency, medication side effect, or other medical condition.

Most people naturally lose 50 to 100 hairs each day. This is a normal part of the hair growth cycle because new hairs are continually replacing those that are shed. Hair loss becomes noticeable when the normal cycle is disrupted, hair follicles become damaged, or new hair growth slows.

Common Causes of Hair Loss

Hair loss (also called alopecia) has many possible causes, including:

• Family history (genetics)

• Hormonal changes

• Thyroid disorders

• Iron deficiency or other nutritional deficiencies

• Significant weight loss

• Physical or emotional stress

• Pregnancy and childbirth

• Menopause

• Certain medications

• Autoimmune diseases

• Scalp inflammation or infection

• Tight hairstyles that place excessive tension on the hair

Because treatment depends on the underlying cause, it is important to consult your healthcare provider if you experience persistent or excessive hair loss.

Hormones and Hair Loss

One of the most common causes of hereditary hair loss is androgenetic alopecia, also known as male or female pattern hair loss.

A hormone called dihydrotestosterone (DHT) is believed to play a major role. DHT is produced when the enzyme 5-alpha reductase converts testosterone into its more active form. In genetically susceptible individuals, DHT gradually causes hair follicles to shrink (miniaturize), resulting in finer, shorter hairs and eventually reduced hair growth.

Both men and women produce testosterone and DHT, although women typically have much lower levels. Hair loss is not determined solely by hormone levels; genetics and an individual's sensitivity of hair follicles to DHT are also important factors.

Hormonal changes associated with aging, menopause, pregnancy, polycystic ovary syndrome (PCOS), and certain medications may all contribute to hair thinning.

Common Types of Hair Loss

Androgenetic Alopecia

This is the most common type of hair loss.

Women often notice gradual thinning over the top of the scalp while maintaining the frontal hairline. Men more commonly develop a receding hairline and thinning at the crown. Genetics plays the largest role in determining who develops this condition.

Telogen Effluvium

Telogen effluvium occurs when a significant physical or emotional stress causes an unusually large number of hairs to enter the resting (telogen) phase of the hair cycle.

Common triggers include:

• Childbirth

• Major surgery

• Severe illness or infection

• Rapid weight loss

• Nutritional deficiencies

• Significant emotional stress

Hair shedding usually begins six weeks to three months after the triggering event. Fortunately, this condition is often temporary, and hair typically regrows once the underlying cause has resolved.

Anagen Effluvium

Anagen effluvium results from injury to actively growing hair follicles. It most commonly occurs during chemotherapy because cancer treatments target rapidly dividing cells, including hair follicles.

Hair loss often begins within weeks after treatment starts and is frequently reversible after therapy is completed.

Traction Alopecia

Traction alopecia is caused by prolonged tension on the hair follicles from tight hairstyles such as tight ponytails, braids, cornrows, extensions, or buns.

When recognized early, reducing tension on the hair usually allows normal hair growth to return. Long-standing traction, however, can result in permanent follicle damage.

Supporting Healthy Hair Growth

Healthy hair begins with a healthy body. Supporting hair growth may include:

• Eating a balanced, protein-rich diet

• Correcting iron, vitamin, or mineral deficiencies when present

• Managing thyroid or hormonal disorders

• Treating scalp inflammation or infection

• Avoiding excessive heat and harsh chemical treatments

• Limiting hairstyles that place constant tension on the hair

• Managing stress and getting adequate sleep

Because hair loss has many possible causes, treatment should always be individualized. A thorough medical evaluation can often identify reversible factors and help determine the most appropriate treatment plan for restoring healthy hair growth.