Hair loss becomes a concern when you notice more shedding than usual, new bald patches, or a gradually thinning scalp. Losing between 50 and 150 hairs per day is normal, so finding strands on your pillow or in the shower drain doesn’t automatically signal a problem. But if you’re seeing clumps in your brush, widening parts, or smooth bare spots, something beyond ordinary shedding is likely happening. The key to figuring out whether you have alopecia is recognizing the specific pattern, location, and speed of your hair loss, because each type looks and behaves differently.
Smooth, Round Patches: Alopecia Areata
Alopecia areata is an autoimmune condition, and it has the most distinctive appearance of any hair loss type. Hair falls out in small, round or oval patches roughly the size of a quarter. These patches appear suddenly, sometimes over just a few days. The bare skin underneath typically looks smooth and normal, with no redness, rash, or scarring.
The most telling sign is what happens at the edges of the patch. You’ll often see short, broken hairs called “exclamation point” hairs. These are narrower at the base than the tip, almost like tiny exclamation marks stuck in the scalp. If you can see these around the border of a bald spot, alopecia areata is very likely.
One or two patches on the scalp is the most common presentation, but the condition can also affect eyebrows, eyelashes, beards, and body hair. In more severe forms, it can progress to total scalp hair loss or total body hair loss. About 20% to 30% of people with alopecia areata also develop changes in their fingernails or toenails: tiny pits on the nail surface, rough texture, white spots, ridging, or brittleness. Nail changes are more common in people with extensive hair loss, so check your nails if you suspect this condition.
Gradual Thinning: Pattern Hair Loss
The most common form of alopecia is androgenetic alopecia, often called male or female pattern hair loss. Unlike alopecia areata, this doesn’t appear overnight. It develops slowly over months or years, and the pattern differs between men and women.
In men, the earliest sign is a receding hairline at the temples, creating a more prominent widow’s peak. This is sometimes subtle enough to dismiss. As it progresses, the hairline takes on an M or V shape, and thinning begins at the crown. Eventually the thinning areas at the front and crown expand toward each other. In the most advanced stage, only a horseshoe-shaped band of hair remains around the sides and back of the head.
In women, the pattern is different. Rather than a receding hairline, you’ll notice a widening part line or overall thinning across the top of the scalp. The frontal hairline usually stays intact. You might first notice it when your ponytail feels thinner, or when you can see more scalp than usual under bright light or in photos taken from above.
If your hair loss follows either of these predictable patterns, is gradual, and runs in your family, pattern hair loss is the most likely explanation.
Sudden, Diffuse Shedding After Stress
If your hair started falling out all over your head (not in patches, not just at the temples) roughly two to three months after a major stressor, you’re likely dealing with telogen effluvium. This is a reactive type of hair loss triggered by events like surgery, severe illness, high fever, significant weight loss, childbirth, or intense emotional stress.
The hallmark is the timing. Your body pushes a large number of hair follicles into a resting phase all at once, and those hairs fall out together about two to three months later. You’ll notice dramatically more hair in the shower, on your brush, and on your clothes. The shedding is diffuse, meaning it comes from all over the scalp rather than from one specific area.
Acute telogen effluvium typically lasts fewer than six months and resolves on its own once the triggering event passes. If you can trace your shedding back to a specific event roughly three months earlier, this is the most likely cause.
Hair Loss Along Your Hairline From Styling
Traction alopecia results from repeated pulling or tension on the hair, and it has a very specific location pattern. The hair loss appears wherever the mechanical force is greatest, which is usually along the edges of the scalp.
Tight ponytails tend to cause thinning at the front and sides. Tight buns pull on the sides and back. Cornrows, braids, and dreadlocks cause hair loss between the rows. Weaves and extensions can cause damage wherever they’re attached. The earliest warning signs include soreness, itching, or increased flaking in the areas under tension, along with small white flakes clinging to the hair shafts near the scalp (called hair casts).
One useful clue is the “fringe sign”: within the thinning area, very short fine hairs closest to the tension may be gone, but a rim of slightly longer hairs remains at the far edge of the patch, away from the pull. The skin underneath usually looks normal in early stages, but if tension continues, you may see redness and small bumps near the bald patches. Caught early, traction alopecia is reversible by changing hairstyles. Left too long, the follicles can scar permanently.
Redness, Scarring, or Pain on the Scalp
Most types of hair loss leave the scalp looking normal. If your bare patches come with visible inflammation, that changes the picture significantly. Scarring alopecia (also called cicatricial alopecia) is a group of conditions where inflammation destroys hair follicles and replaces them with scar tissue. The hair loss is permanent because the follicles themselves are gone.
Signs that point toward scarring alopecia include skin that looks smooth and shiny where hair has been lost, with no visible follicle openings. You might also experience burning, tenderness, itching, crusting, scaling, blistering, or redness around the affected areas. Some people notice pustules or discoloration on the scalp. This is distinctly different from alopecia areata, where bare patches look like normal skin with visible pore openings.
If your hair loss comes with any pain, burning, or visible skin changes, getting evaluated promptly matters. Early treatment can slow or stop the scarring process, but follicles that are already destroyed won’t grow back.
What a Dermatologist Looks For
A dermatologist can often identify the type of alopecia just by examining your scalp, looking at the pattern and location of hair loss, and checking whether follicle openings are still visible. They may use a dermoscope, a magnifying tool that reveals details invisible to the naked eye. In alopecia areata, this shows black dots, broken hairs, exclamation-mark hairs, and yellow dots (follicle openings filled with oil). In pattern hair loss, the follicles are still present but producing progressively finer, thinner hairs.
When the cause isn’t obvious from the exam, blood tests can help rule out underlying conditions. Common tests check ferritin levels (which reflect iron stores in the body), thyroid-stimulating hormone (to screen for thyroid disease), and androgen levels in women with diffuse thinning. Nutritional deficiencies and hormonal imbalances are treatable causes of hair loss that would be missed without bloodwork.
In some cases, particularly when scarring alopecia is suspected, a small scalp biopsy may be needed. This involves removing a tiny piece of skin for examination under a microscope to identify the specific type of inflammation affecting the follicles.
Sorting Out Your Symptoms
The fastest way to narrow down what you’re dealing with is to ask yourself a few specific questions. Is the hair loss patchy or diffuse? Coin-sized smooth patches suggest alopecia areata. Overall thinning across the scalp, especially after a stressful event, suggests telogen effluvium. Gradual recession at the temples or a widening part points to pattern hair loss.
Next, consider the timeline. Sudden onset over days to weeks is typical of alopecia areata or telogen effluvium. Slow progression over months to years fits pattern hair loss. Hair loss that corresponds to wearing a particular hairstyle suggests traction alopecia.
Finally, look at the scalp itself. Normal-looking skin with visible pores is reassuring, even if hair is missing. Redness, scaling, pain, or shiny scarred skin signals a more urgent situation that needs professional evaluation. And don’t forget to check your nails: pitting, roughness, or white spots alongside patchy hair loss strengthens the case for alopecia areata.