Diffuse Thinning: What It Is & How to Treat It

Key takeaways:

• Diffuse thinning is spread-out hair loss that affects the entire scalp.

• It can have various causes, from medication side effects and hormonal changes to stress-induced shedding or illness.

• Treatments are available and effective, namely minoxidil and finasteride.

• A healthcare provider can help you figure out the cause and decide which treatment is best.

Hair loss can take many forms, from a receding hairline to a bald patch. Diffuse thinning is among the most common types of hair loss. It affects the entire head of hair rather than a specific area and can give hair a “see-through” appearance.

We’ll explain what diffuse thinning is, how to know if you have it, and the most common causes of diffuse thinning. We’ll also go over ways to stimulate hair growth and restore your hair’s natural thickness and density.

Diffuse thinning (or diffuse hair loss) is a form of hair loss in which hair falls out from all areas of the scalp. It makes hair take on a thin, low-density appearance that almost looks translucent.

Male pattern baldness, the most common cause of hair loss in men, usually starts to develop as a receding hairline or a bald spot at the crown. In contrast, diffuse hair loss usually affects the entire scalp without creating a clear receding hairline or other distinct pattern.

Like other types of hair loss, diffuse thinning can have a noticeable effect not only on the appearance of your hair but also on your quality of life.

→ Read: What Is DUPA (Diffuse Unpatterned Alopecia)?

Like other types of hair loss, diffuse thinning can appear suddenly or develop over several months.

If you’re experiencing diffuse hair loss, you may notice these signs and symptoms:

• Reduced hair density. The most obvious sign of diffuse hair loss is visibly thin hair. Your hair might look less dense than normal, with fewer hairs at your hairline, mid-scalp, and crown.

• Easily visible scalp. As hair density decreases, your scalp may become easier to see. Your scalp might be particularly visible when your hair is wet or when you look at your scalp under bright, downward-facing light.

• Excessive hair shedding. It’s normal to shed between 50 and 100 hairs each day. If you have diffuse thinning, you might lose more hair strands than this on a daily basis. Or you might notice more loose hairs on your pillowcase, bathroom floor, or shower drain.

→ Learn more: Hair Shedding vs. Hair Loss: Understand the Difference

Several different issues can cause or contribute to diffuse thinning. One of the most common is a form of hair shedding called telogen effluvium.

Telogen Effluvum

Telogen effluvium is when a large amount of scalp hairs prematurely enter the resting (telogen) phase of the hair growth cycle.

Healthy hair goes through a multi-phase cycle as it grows to its full length:

• Anagen phase. In the anagen phase, each hair grows from the hair follicle to its full length over the course of two to six years. 

• Catagen phase. The hair then enters the catagen phase — a transition stage in which the hair stops actively growing. 

• Telogen phase. Finally, the hair enters the telogen phase. This is when growth stops.

• Exogen phase. The hair falls out and is replaced by a new strand of anagen hair.

Normally, 80 to 90 percent of the hair on your scalp is in the anagen phase at any time, with the remaining hair in the telogen phase.

With telogen effluvium, as much as 70 percent of all anagen hairs prematurely enter into the telogen phase. This means growth stops, and within a few months, those hairs fall out.

→ Learn more: The Hair Growth Cycle: 4 Stages Explained

Telogen Effluvum Causes

Most cases of telogen effluvium are in response to physiologic stress, which can be caused by various factors.

Things that may trigger telogen effluvium:

• Illnesses that cause fever

• Infections, major surgery, or injuries

• Sudden changes in hormone levels

• Chronic stress

• Traumatic events

• Thyroid conditions, such as hypothyroidism

• Crash diets that significantly reduce food intake

• Nutritional deficiencies, such as low protein intake or iron deficiency

• Side effects of medications, such as beta-blockers, retinoids, and anticoagulants

Hair shedding from telogen effluvium isn’t permanent. Typically, hair will start to grow back once the underlying issue is treated (or has passed).

Other Causes of Diffuse Thinning

Although telogen effluvium is a common cause of diffuse thinning, it isn’t the only issue that can result in this type of hair loss. Other potential causes of diffuse thinning include:

• Male pattern baldness. Male pattern hair loss can cause a receding hairline, balding at the crown, or diffuse hair loss that affects most of the scalp. Men in the later stages of the Norwood scale often have visible, significant diffuse thinning.

• Alopecia areata incognita. This type of autoimmune hair loss (alopecia areata) causes sudden hair shedding, sometimes in patchy patterns or all over. It can develop over the course of a few weeks and is often misdiagnosed as telogen effluvium or male pattern baldness.

• Diffuse alopecia areata. This form of alopecia areata happens over a longer period. It also causes diffuse thinning that can affect the entire scalp.

• Anagen effluvium. Anagen effluvium is a form of nonscarring hair loss that can develop in response to certain medications and chemicals, including chemotherapy.

Like other forms of hair loss, diffuse thinning is almost always treatable with medication, lifestyle changes, hair loss products, or a combination of approaches.

Let’s go over the most effective ways to treat diffuse thinning.

Treat the Underlying Cause

When diffuse thinning is caused by telogen effluvium, it’ll usually improve on its own several months after the triggering event or once you treat or address the underlying issue.

This could mean:

• Making changes to medical treatments or medications you’re using

• Adjusting your diet

• Reducing stress

• Resting and recovering after an injury or surgery

If you think you might have telogen effluvium, talk to your healthcare provider or schedule an appointment with a dermatologist.

They can test your hair for signs of telogen effluvium using a pull test and biopsy. Many common causes of telogen effluvium can be identified with a complete blood count, a thyrotropin test, and other quick blood tests.

Minoxidil for Diffuse Thinning

Minoxidil (the active ingredient in Rogaine^®) is an FDA-approved, over-the-counter topical hair loss medication. Experts think it works by shifting hairs into the growth phase of the hair growth cycle and stimulating blood flow to the scalp.

If you have diffuse hair loss, applying minoxidil to your scalp might help stimulate new hair growth and produce thicker, denser hair.

In a 12-month study, 84.3 percent of balding men who used minoxidil rated it as “very effective,” “effective,” or “moderately effective” at promoting hair regrowth.

We offer minoxidil online in the form of foam or a liquid solution. Although oral minoxidil isn’t over the counter (you need a prescription), it could be an option following a consultation with a licensed healthcare provider.

→ Read next: How Long Does Minoxidil Take to Work?

Finasteride for Diffuse Thinning

Oral finasteride is an FDA-approved prescription hair loss medication. It comes in tablet form and works by blocking the effects of 5-alpha reductase (5AR), an enzyme that converts testosterone into dihydrotestosterone (DHT).

DHT is a hormone responsible for shrinking (miniaturizing) hair follicles in the scalp and causing male pattern baldness.

Finasteride is very effective, but only for hair loss caused by DHT — which is usually genetic and age-related.

If you’re interested in trying it out, you can see if you’re eligible for a prescription and get finasteride online after a consultation with a medical provider.

Topical Minoxidil and Finasteride

These two are a dynamic duo for treating hair loss and diffuse thinning. Research shows that hair growth results are even more significant when minoxidil and finasteride are used together.

Other Hair Growth Products

Currently, FDA-approved hair loss medications (topical minoxidil and oral finasteride, that is) are the most effective treatment options for thinning hair.

That said, other hair growth products can also help control excessive shedding and promote healthy hair growth:

• Growth-promoting shampoo. Many shampoos are formulated for stronger hair growth and a healthy scalp, with ingredients like saw palmetto and ketoconazole. Our hair thickening shampoo targets DHT buildup on the scalp and supports other hair loss treatments.

• Biotin and other hair growth vitamins. Several vitamins and minerals play key roles in growing thick, strong, and healthy hair. Our biotin gummies contain not only vitamin B7 but also niacin, folate, and other essential nutrients for hair.

→ Learn more: The Best Minerals and Vitamins for Hair Growth

Here’s what to keep in mind about diffuse thinning:

• Diffuse thinning is excessive shedding or hair loss that affects the entire scalp evenly rather than only in specific areas.

• Several forms of hair loss, including telogen effluvium, male pattern baldness, and alopecia areata, can show up as diffuse thinning.

• If you’ve noticed your hair looking thinner than normal, talk to your healthcare provider or schedule an appointment with a dermatologist to identify the cause.

• Most of the time, hair loss treatments like minoxidil and finasteride can stop hair loss, prevent diffuse thinning from getting worse, and help regrow lost hair.

→ Read next: What Are The Early Signs of Balding?