A bald spot on your head is most commonly called alopecia areata when it appears as a distinct, round patch of hair loss. “Alopecia” is simply the medical term for hair loss of any kind, and doctors use more specific names depending on the cause, pattern, and location. If you’ve noticed a smooth, coin-sized bare patch on your scalp, alopecia areata is the most likely term your doctor would use. But not every bald spot has the same cause or the same name.
Alopecia Areata: The Classic Bald Patch
Alopecia areata is an autoimmune condition where your immune system mistakenly attacks hair follicles, causing inflammation that shuts down hair production in a localized area. It typically begins as one or more round or oval patches of sudden hair loss on the scalp, though it can also affect the beard, eyebrows, or eyelashes. The skin in the bare patch usually looks smooth and normal, with no rash, redness, or scarring.
One telltale sign is the presence of “exclamation point” hairs around the edges of the patch. These are short, broken strands that are narrower at the base than the tip, almost like tiny exclamation marks stuck in the skin. Some people also develop small pits or dents in their fingernails, particularly when hair loss is more extensive.
The condition affects roughly 0.2% of the global population at any given time, but lifetime risk is surprisingly high. By 2021, an estimated 32% of women and 17% of men worldwide faced some risk of developing alopecia areata during their lives. The good news: hair follicles aren’t permanently destroyed. About 34% to 50% of people with patchy hair loss experience spontaneous regrowth within one year without any treatment. First-line treatment for those who do seek help typically involves corticosteroid creams or injections applied directly to the patches every four to six weeks.
Androgenetic Alopecia: Thinning at the Crown
If the bald spot you’re noticing is a gradual thinning area at the top-back of your head rather than a sudden smooth patch, it’s likely androgenetic alopecia, commonly known as male or female pattern baldness. The area at the very top and back of the head is called the vertex (also referred to as the crown), and it’s one of the primary zones where this type of hair loss shows up.
The mechanism here is hormonal, not autoimmune. An enzyme converts testosterone into a more potent hormone called DHT, which binds to receptors in scalp hair follicles with about five times the strength of regular testosterone. Over time, this shrinks the follicles and produces thinner, shorter hairs until the follicle stops producing visible hair altogether. At the vertex, the loss typically starts at a central point and spreads outward in a circular pattern. This is why many people first notice a small “bald spot” at the crown that gradually widens over months or years.
Traction Alopecia: Bald Spots From Tension
Bald spots that appear along your hairline, temples, or above your ears often point to traction alopecia. This is hair loss caused by repeated pulling or tension on the hair from tight hairstyles like ponytails, braids, cornrows, or extensions. The frontal and temporal scalp are the most commonly affected areas, though tight cornrow patterns can cause loss in other zones as well.
Unlike alopecia areata, traction alopecia develops gradually and follows the line of tension rather than forming a random round patch. Early on, the damage is reversible if the pulling stops. But years of repeated stress on the same follicles can cause permanent scarring and irreversible hair loss in those areas.
Tinea Capitis: Bald Spots From Fungal Infection
A bald patch that looks irritated, scaly, or itchy is more likely tinea capitis, a fungal infection of the scalp. It presents as one or more patches of hair loss, sometimes with a distinctive “black dot” pattern where hairs have broken off right at the scalp surface. Unlike the smooth, clean patches of alopecia areata, tinea capitis patches are often accompanied by scaling, redness, small pustules, and noticeable itching.
This condition is most common in children and is contagious. Under magnification, the broken hairs in a fungal infection tend to have comma or corkscrew shapes, which look quite different from the exclamation point hairs seen in alopecia areata. Treatment requires antifungal medication rather than corticosteroids, so getting the right diagnosis matters.
How to Tell Which Type You Have
The appearance of the bald spot itself gives strong clues about its cause:
- Smooth, round, no redness: alopecia areata. Look for exclamation point hairs at the edges.
- Gradual thinning at the crown: androgenetic alopecia, especially if you have a family history of pattern baldness.
- Along the hairline or temples: traction alopecia, particularly if you wear tight hairstyles.
- Scaly, itchy, inflamed: tinea capitis or another infection, especially in children.
A dermatologist can often identify the type by examining the patch and the surrounding hairs, sometimes using a dermatoscope (a magnifying tool) to look at hair shaft patterns. In uncertain cases, a small scalp biopsy or fungal culture can confirm the diagnosis. The name your bald spot gets determines the treatment path, so identifying the right type is the most important first step.