Hair Thinning & Loss

Understanding Hair Thinning and Loss

If your hair feels thinner than it used to, you are far from alone. Hair thinning and loss are among the most common reasons people seek medical evaluation, and they affect both men and women across a wide range of ages. Losing roughly 50 to 100 hairs per day is normal. But a noticeable drop in density, a widening part, a receding hairline, or visible patches of loss can point to an underlying issue worth attention. Your hair reflects the health of your whole body, so a change in it is sometimes the first visible sign of a hormonal, nutritional, or metabolic imbalance.

At ENNU Life in Louisville, Kentucky, we look at hair concerns as part of the bigger picture of your hormonal and metabolic health rather than treating them on their own.

How Hair Growth Works

Each hair follicle moves through three main phases: anagen (active growth, lasting years), catagen (a brief transition), and telogen (rest and shedding). At any given time, most of your follicles are in the growth phase. Many forms of hair loss happen when this cycle is disrupted. More follicles get pushed into the resting and shedding phases, or the growth phase gets shorter so hairs become finer with each cycle.

Common Causes of Hair Thinning and Loss

Hair loss is not one condition. It is a symptom with many possible drivers. Common, well-established causes include:

• Androgenetic alopecia (male- and female-pattern hair loss): a genetically influenced sensitivity of follicles to androgens, producing gradual miniaturization of hair, typically at the crown, temples, or along the part line.
• Telogen effluvium: diffuse shedding triggered by a physiologic stressor such as illness, surgery, significant weight loss, childbirth, or emotional stress, usually appearing two to three months after the trigger.
• Thyroid disorders: both underactive (hypothyroid) and overactive (hyperthyroid) states can cause diffuse thinning.
• Nutritional deficiencies: low iron stores, vitamin D, zinc, or inadequate protein intake can impair hair growth.
• Hormonal changes: shifts in estrogen, progesterone, testosterone, or DHT, including those around menopause or with conditions such as polycystic ovary syndrome.
• Autoimmune conditions such as alopecia areata, which causes well-defined patches of loss.
• Medications and medical treatments, certain scalp conditions, and tight hairstyling practices.

Relevant Lab Markers

Because so many causes start on the inside, lab testing often guides effective treatment. A clinician may look at markers such as a complete blood count, ferritin (iron stores), a thyroid panel (including TSH and free thyroid hormones), vitamin D, and, when appropriate, sex hormones such as testosterone, DHEA-S, and others. Reference ranges are assay-dependent and vary between laboratories, so your results should always be read by a clinician in the context of your symptoms and history, not measured against a single fixed number.

When to Seek Evaluation

Consider a professional evaluation if you notice any of the following:

• Sudden, rapid, or patchy hair loss
• A widening part, thinning crown, or receding hairline
• Shedding accompanied by fatigue, weight changes, cold or heat intolerance, or menstrual changes
• Scalp redness, scaling, itching, pain, or scarring
• Hair loss that is causing significant distress

Scarring forms of hair loss, in particular, are best evaluated early, because follicles that are permanently damaged cannot regrow.

How Hair Loss Is Approached Clinically

A thorough evaluation usually begins with a detailed history and scalp examination, followed by targeted lab testing to find reversible contributors. Treatment depends entirely on the cause. Correcting a thyroid imbalance, replenishing iron or vitamin D, addressing a hormonal shift, or allowing a telogen effluvium to resolve can each restore healthier growth. For pattern hair loss, clinicians may discuss established medical therapies and realistic expectations about slowing progression and improving density over time. Because hair grows slowly, meaningful results generally take several months of consistent care.

Take the Next Step

Hair thinning is often a window into your overall hormonal and metabolic health. A structured assessment is the most reliable way to understand what is driving your symptoms and what can be done about it.

Start your ENNU Life Health Assessment

Educational only, not medical advice; consult a licensed clinician.