Bald spots develop when something disrupts the normal hair growth cycle in a localized area of your scalp. The most common cause is an autoimmune condition called alopecia areata, which affects about 2% of the global population. But bald spots can also result from fungal infections, tight hairstyles, compulsive hair pulling, or scarring conditions. The cause determines whether the hair loss is temporary or permanent, so identifying the right one matters.
Alopecia Areata: The Most Common Cause
Alopecia areata produces smooth, round bald patches that seem to appear out of nowhere. The underlying problem is your immune system mistakenly attacking your own hair follicles. Normally, hair follicles have a kind of immune protection that keeps them hidden from your body’s defense system. In alopecia areata, that protection breaks down, and immune cells swarm the follicle in a pattern pathologists describe as a “swarm of bees” under the microscope. The attack is led primarily by a type of white blood cell that directly kills the cells responsible for growing hair.
The good news is that alopecia areata is often temporary. In more than 90% of cases, hair grows back and fills the bald spot within one year, even without treatment. The follicles aren’t destroyed. They’re essentially forced into a dormant state by the immune attack, and once the inflammation subsides, they can resume producing hair. Some people experience a single episode and never have another. Others develop recurring patches over months or years.
Under magnification, a dermatologist can spot telltale signs of alopecia areata: short, tapered hairs that are thicker at the top and thinner near the root (called “exclamation mark hairs”), tiny yellow dots where follicles are clogged with oil, and uniform black dots where hairs have broken at the scalp surface. These features help distinguish it from other causes of bald spots.
Fungal Infections of the Scalp
Ringworm of the scalp (tinea capitis) is a fungal infection that creates patchy hair loss, especially in children. The fungus attacks the outer layer of scalp skin and the hair shaft itself, making hairs brittle and fragile. They snap off at or just above the scalp, leaving behind one or more round, scaly patches studded with small black dots where the broken hair stubs remain.
Unlike alopecia areata, fungal bald spots are rarely smooth. The skin looks scaly and silvery, and the area is often tender or painful to touch. In severe cases, a swollen, pus-filled mass called a kerion can form, creating thick yellow crusting on the scalp. Ringworm is contagious and spreads through direct contact or shared combs, hats, and pillows. It requires antifungal treatment to clear, but hair typically regrows once the infection is resolved.
Tight Hairstyles and Traction Alopecia
Persistent pulling on hair follicles from tight hairstyles can create bald spots along the hairline, temples, or wherever tension is greatest. This is called traction alopecia, and it develops gradually. Cornrows, locs, tight braids, slicked-back ponytails, buns, and hair extensions or weaves are all common culprits, particularly when worn tightly over weeks or months. Even the constant rubbing of a hat or headscarf can contribute, especially if the hair underneath is pulled back.
The critical factor is duration. Dermatologists recommend wearing braids for no longer than six to eight weeks and keeping weaves in for short periods. When pulling continues long enough, the follicles become permanently damaged. Where you once had hair, you’ll see shiny, smooth skin that will not regrow hair regardless of treatment. Caught early, traction alopecia is reversible. Left untreated, it becomes permanent.
Hair Pulling From Trichotillomania
Trichotillomania is a condition where a person repeatedly pulls out their own hair, often without fully realizing they’re doing it. It creates irregular bald patches that look different from alopecia areata under close inspection. The broken hairs are at different lengths above the scalp, reflecting the varied timing of pulling episodes, whereas in alopecia areata the broken hairs tend to be more uniform. The black dots left behind in trichotillomania also vary in size and shape, while those from alopecia areata are more consistent.
This distinction matters because the treatments are completely different. Alopecia areata responds to immune-targeted therapies, while trichotillomania requires behavioral approaches. A dermatologist can usually tell them apart by examining the patch closely, sometimes using a magnifying instrument called a dermatoscope.
Stress and Diffuse Thinning
Severe physical or emotional stress can trigger a type of hair loss called telogen effluvium, where a large number of hair follicles simultaneously shift into their resting phase and shed two to three months later. However, this type of hair loss is typically diffuse, meaning it thins hair across the entire scalp rather than creating distinct bald spots. If you’re noticing a clearly defined circular patch, stress alone is unlikely to be the explanation.
That said, stress may play a role in triggering or worsening alopecia areata in people who are already predisposed to it. The relationship between stress and autoimmune flares is well established, so a stressful event followed by a bald spot appearing weeks later isn’t coincidental for some people.
Scarring Conditions That Destroy Follicles
Some bald spots result from conditions that permanently scar the follicle, making regrowth impossible. Discoid lupus, lichen planopilaris, and a condition called dissecting cellulitis of the scalp all fall into this category. Under magnification, scarring hair loss shows white dots on the scalp surface, which correspond to follicles that have been replaced by scar tissue. These white dots become more common as the condition persists over years.
Scarring alopecia tends to look and feel different from non-scarring types. The skin in the affected area may appear shiny, discolored, or slightly indented. There’s sometimes redness or tenderness at the edges of the patch where active inflammation is still occurring. Early treatment can prevent further spread, but hair that’s already lost from scarring typically won’t return.
How to Tell What’s Causing Your Bald Spot
The appearance of the bald spot itself gives important clues. A smooth, round patch with no scaling or redness is classic for alopecia areata. Scaly, flaky skin with broken hair stubs and tenderness points toward a fungal infection. Bald areas along the hairline or wherever a tight style pulls hardest suggest traction alopecia. Irregular patches with hairs broken at varying lengths may indicate hair pulling.
A dermatologist can narrow the diagnosis quickly using a dermatoscope, a handheld magnifying tool that reveals features invisible to the naked eye. In some cases, a small skin biopsy or a fungal culture may be needed. The sooner you identify the cause, the better your chances of reversing the hair loss, since several of these conditions become permanent only when they go untreated for too long.