Hair loss is rarely random. Understanding the underlying cause is the first step toward an effective treatment plan. Here are the most common root causes we see in our consultations.
5 min read
Reviewed by Dr. Leonard
Root Causes
The Most Common Drivers
Tap any cause to learn more about how it works and what treatment looks like.
Genetics (Androgenetic Alopecia)
The single most common cause of long-term hair loss, but also one of the most treatable when addressed early.
Androgenetic alopecia is driven by an inherited sensitivity to dihydrotestosterone (DHT), a hormone that gradually miniaturizes follicles on the scalp. It can begin in your teens or emerge decades later. Both men and women are affected, though the pattern of loss looks different. Early intervention with doctor-led treatments can slow or reverse progression.
Hormonal Changes
Pregnancy, postpartum, perimenopause, thyroid disorders, and PCOS can all disrupt the hair growth cycle.
Hormonal shifts alter how long hair stays in its growing (anagen) phase. Many women experience noticeable shedding 2–4 months after childbirth, or as estrogen levels change with age. Thyroid imbalances and PCOS are common underlying drivers that often go undiagnosed.
Stress & Illness (Telogen Effluvium)
Major life events, surgery, fever, or chronic stress can push large numbers of follicles into the shedding phase.
Telogen effluvium typically shows up 2–4 months after the triggering event and presents as diffuse shedding across the entire scalp. In most cases it's reversible — but identifying the trigger and supporting regrowth with proper treatment accelerates recovery significantly.
Nutrition & Diet
Low iron, vitamin D, B12, protein, or zinc can all starve follicles of the building blocks they need.
Hair is one of the first tissues the body de-prioritizes when nutrients run low. Restrictive diets, rapid weight loss, GLP-1 medications, and iron deficiency are among the most common nutritional causes of shedding we see at our consultations.
Medications
Some medications — including GLP-1s, certain antidepressants, beta blockers, and chemotherapy — can trigger shedding.
Medication-induced hair loss is usually temporary and improves once the medication is adjusted or stopped. But it's important to rule out other underlying causes before assuming medication is to blame. A consultation can help you map symptoms to the right cause.
Scalp Health
Chronic inflammation, seborrheic dermatitis, product buildup, and poor circulation all impact follicle function.
A healthy scalp is the foundation of healthy hair. Flaking, itching, soreness, and excessive oiliness are signals that the environment around your follicles needs support. Targeted treatments restore balance and let follicles do their job.
