Why Is My Hair Falling Out? 10 Possible Causes of Hair Loss and Excessive Shedding

You wash your hair and notice more strands than usual in the shower.

Your hairbrush seems fuller. You find hairs on your pillow, clothes or around the house. Perhaps your hairline looks different, your part appears wider, or your hair simply does not feel as thick as it used to.

Naturally, you may start wondering:

Why is my hair falling out?

Some hair shedding is completely normal. The NHS says people can normally lose around 50 to 100 hairs a day, often without noticing.

But noticeably increased shedding, gradual thinning or bald patches can have many different causes.

Stress, illness, genetics, hormonal changes, iron deficiency, thyroid problems, medications and even certain hairstyles can all play a role.

The pattern of your hair loss—and what happened in the months before it began—can provide important clues.

Here are 10 possible reasons your hair may be falling out.

1. It May Be Normal Hair Shedding

Hair does not remain attached to your scalp forever.

Individual hairs naturally move through a cycle of:

• growth
• transition
• rest
• shedding

This means finding some hair in your brush or shower is expected.

The American Academy of Dermatology also considers shedding around 50 to 100 hairs per day normal.

Rather than trying to count every strand, pay attention to changes from what is normal for you.

You may have excessive shedding if you suddenly notice much more hair than usual coming out during washing or brushing.

2. Stress Can Trigger Temporary Hair Shedding

Major physical or emotional stress can disrupt the normal hair-growth cycle.

This can cause a condition known as telogen effluvium, where more hairs than usual move into the resting and shedding phase.

Potential triggers include:

• major emotional stress
• surgery
• severe illness
• high fever
• major life events
• significant physical stress

One confusing feature is the timing.

The excessive shedding may not begin immediately after the stressful event. It can become noticeable several weeks or months later. Cleveland Clinic notes that major shedding seen today may reflect something that happened roughly three months earlier.

So when investigating sudden shedding, think back over the previous few months rather than only the previous few days.

3. Recent Illness Can Cause Your Hair to Shed

A significant illness can temporarily interrupt the hair-growth cycle.

You might recover from an infection or fever and feel completely well again—only to notice increased hair shedding later.

Possible triggers can include:

• a high fever
• a significant infection
• major surgery
• serious illness
• substantial physical stress on the body

This type of shedding is often temporary.

The NHS notes that some forms of temporary hair loss can be associated with illness and may improve after recovery.

4. Rapid Weight Loss or Restrictive Dieting Could Be Involved

Hair growth requires energy, protein, vitamins and minerals.

Rapid weight loss or an extremely restrictive diet can sometimes disrupt normal hair growth.

This may be particularly relevant if you have recently:

• lost substantial weight quickly
• dramatically reduced your calorie intake
• followed a very restrictive diet
• had difficulty eating because of illness
• undergone a major change in nutrition

The NHS includes weight loss among potential causes of temporary hair loss.

Hair loss after weight loss does not necessarily mean one particular vitamin is missing.

The overall nutritional picture matters.

5. Iron Deficiency Could Contribute to Hair Loss

Iron deficiency is another recognised potential cause of hair loss.

If iron deficiency has progressed to iron-deficiency anaemia, you may also experience symptoms such as:

• tiredness
• weakness
• shortness of breath
• dizziness
• palpitations
• paler skin than usual

However, hair loss does not automatically mean you need iron supplements.

Taking supplements without knowing whether you are deficient is not the best approach.

If your symptoms suggest iron deficiency, a healthcare professional can arrange appropriate blood tests.

Related reading: Why Am I Always Cold? 9 Possible Reasons You Feel Cold All the Time

6. Your Thyroid Could Be Involved

Thyroid hormones influence many processes throughout your body, including the hair-growth cycle.

Both overactive and underactive thyroid conditions can affect hair.

An underactive thyroid may also cause symptoms such as:

• persistent tiredness
• feeling unusually cold
• weight gain
• constipation
• difficulty concentrating
• dry skin

Hair loss by itself cannot diagnose a thyroid condition.

But hair changes occurring alongside several other possible thyroid symptoms are worth discussing with a healthcare professional.

7. Hormonal Changes Can Affect Your Hair

Hormonal changes can temporarily or progressively affect hair growth.

One well-known example occurs after childbirth.

During pregnancy, hormonal changes can keep more hairs in their growth phase. After delivery, those hormone levels change, and many hairs can enter the shedding phase.

The result can look dramatic.

The NHS notes that women commonly lose more hair than usual during the months after giving birth.

Other hormonal transitions may also influence hair, including menopause.

The important point is that increased shedding after a hormonal change does not automatically mean the hair follicles have permanently stopped producing hair.

8. It Could Be Male or Female Pattern Hair Loss

Not all hair loss is temporary.

Androgenetic alopecia, commonly called male-pattern or female-pattern hair loss, is largely influenced by genetics and hormones.

The pattern can differ.

In men

Hair loss commonly involves:

• a receding hairline
• thinning around the temples
• thinning at the crown

In women

It may appear as:

• gradually reduced hair density
• a widening part
• thinning over the top of the scalp

The NHS describes male and female pattern baldness as permanent types of hair loss that commonly run in families.

Gradual thinning over several years therefore means something different from suddenly losing large amounts of hair over several weeks.

9. Alopecia Areata Can Cause Bald Patches

If your hair is disappearing in distinct patches rather than gradually thinning everywhere, another possibility is alopecia areata.

This is an autoimmune condition in which the immune system attacks hair follicles.

It can produce smooth, round or oval bald patches.

Hair loss may affect:

• the scalp
• eyebrows
• eyelashes
• facial hair
• other areas of the body

The American Academy of Dermatology notes that alopecia areata can cause hair loss anywhere on the body.

Sudden bald patches deserve professional assessment because there are several possible causes of patchy hair loss.

10. Your Hairstyle or Hair-Care Routine Could Be Damaging Your Hair

Sometimes the problem is external rather than internal.

Hairstyles that repeatedly pull tightly on the hair follicles can cause traction alopecia.

Examples may include consistently tight:

• braids
• ponytails
• extensions
• weaves
• other tension-producing styles

Repeated chemical treatments and excessive heat can also damage hair and contribute to breakage.

Cleveland Clinic specifically identifies tight hairstyles and repeated harsh hair-care practices among potential causes of hair loss and damage.

Persistent traction can eventually damage follicles, so early recognition matters.

Why Is My Hair Suddenly Falling Out So Much?

Sudden widespread shedding often makes people panic because the amount of hair can appear dramatic.

Think back approximately two to four months.

Did you experience:

• a severe illness?
• high fever?
• surgery?
• major emotional stress?
• childbirth?
• rapid weight loss?
• a significant dietary change?
• a new medication?

Temporary excessive shedding can appear after one of these triggers.

A September 2026 physician-reviewed INTEGRIS Health article similarly notes that increased shedding can appear after stress, illness, childbirth, medication changes or hormonal disruption.

Why Is My Hair Falling Out From the Root?

Seeing a hair come out with a small bulb at one end can be alarming.

But a shed hair does not normally mean that you have pulled the entire living follicle out of your scalp.

The follicle remains within the skin and may produce another hair depending on the underlying condition.

The more important question is whether new hairs continue replacing those that are shed.

Why Is My Hair Getting Thinner but I Don't See Bald Patches?

Hair loss does not always produce obvious bald areas.

Diffuse thinning may make your:

• ponytail feel smaller
• scalp more visible
• part look wider
• overall hair density decrease

Possible explanations include excessive shedding and female-pattern hair loss, among others.

The distribution, speed of progression and medical history can help distinguish them.

Why Is My Hair Falling Out in the Shower?

Washing your hair does not necessarily cause the hairs you see in the shower to fall out.

Many of those strands may already have reached the shedding stage of their natural growth cycle.

Washing simply releases them.

If you wash your hair less frequently, you may notice more shed hairs at once because several days' worth have accumulated.

What matters is whether the overall amount has noticeably increased or your hair density is declining.

Can Dandruff Make Your Hair Fall Out?

Dandruff itself is not usually a direct cause of permanent hair loss.

However, an itchy or inflamed scalp can lead to repeated scratching, which may damage hairs.

There are also scalp conditions that can cause both scaling and hair loss, so significant hair loss accompanied by redness, pain, inflammation or severe scaling should be assessed.

Scalp ringworm, for example, can cause hair loss and requires appropriate treatment. The American Academy of Dermatology notes that untreated scalp ringworm can result in hair loss.

Can Vitamin Deficiency Cause Hair Loss?

Certain nutritional deficiencies can contribute to hair loss.

But this does not mean everyone experiencing hair loss should start taking multiple hair-growth supplements.

Hair loss has many possible causes.

Taking high doses of vitamins without evidence of deficiency may provide no benefit and, in some circumstances, excessive supplementation can itself cause problems.

If nutritional deficiency is suspected, identifying the actual deficiency is more useful than guessing.

Can Medication Cause Hair Loss?

Yes.

Certain medications can cause hair shedding or thinning in some people.

Cancer chemotherapy is one well-known example, but other medications may also contribute.

If your hair loss began after starting a medicine or changing its dose, discuss the timing with your doctor or pharmacist.

Do not stop prescribed medication yourself because you suspect it is causing hair loss.

Will My Hair Grow Back?

That depends entirely on the cause.

Some forms of hair loss are temporary.

For example, hair shedding triggered by illness, stress or another temporary physical event can improve after the underlying trigger resolves.

Other types, including hereditary pattern hair loss, can be progressive.

Some conditions can damage follicles permanently if they are not treated early.

This is why establishing the cause matters more than simply buying a product labelled “hair growth.”

What Can I Do About Excessive Hair Loss?

Look for the pattern

Ask yourself whether the hair loss is:

• sudden or gradual
• patchy or widespread
• mainly at the hairline
• mainly at the crown
• accompanied by scalp symptoms

Think back several months

Consider illnesses, major stress, surgery, childbirth, rapid weight loss or medication changes.

Treat your hair gently

Avoid unnecessary pulling, excessive heat and harsh chemical treatments.

Eat a balanced diet

Hair requires adequate nutrition, including sufficient protein and micronutrients.

Avoid randomly taking supplements

Hair loss does not tell you which nutrient—if any—you are deficient in.

Take photographs

Taking consistent photographs of your hairline, part and crown every few weeks can help you objectively assess whether the problem is progressing.

When Should You See a Doctor About Hair Loss?

Consider seeking medical assessment if:

• your hair suddenly starts falling out heavily
• you develop bald patches
• your hair loss is rapidly worsening
• your scalp is painful, inflamed or severely scaly
• you are losing eyebrows or other body hair
• hair loss occurs alongside persistent tiredness, weight changes or other unexplained symptoms
• you suspect a medication is contributing
• you are worried about the amount of hair you are losing

The NHS advises seeing a GP if you are concerned about hair loss and recommends identifying the cause before approaching a commercial hair clinic.

Frequently Asked Questions

How much hair loss per day is normal?

Around 50 to 100 hairs per day is generally considered normal shedding.

You do not need to count every strand. A noticeable change from your usual shedding pattern is more useful.

Can stress really make your hair fall out?

Yes. Significant emotional or physical stress can trigger temporary excessive shedding.

The shedding may not become obvious until several months after the stressful event.

Can losing weight cause hair loss?

Yes. Significant or rapid weight loss can sometimes trigger temporary hair shedding, particularly when accompanied by inadequate nutrition.

Can low iron make your hair fall out?

Iron deficiency can contribute to hair loss.

However, hair loss alone does not establish iron deficiency, so testing may be appropriate before taking supplements.

Does thyroid disease cause hair loss?

Thyroid disorders can affect the hair-growth cycle and cause thinning or increased shedding.

Can tight braids cause permanent hair loss?

Repeated tension from tight hairstyles can cause traction alopecia.

If the pulling continues for a prolonged period and follicles become permanently damaged, some hair loss may become irreversible.

Should I use hair-growth supplements?

Not automatically.

Supplements are most useful when an actual deficiency has been identified. Hair loss caused by genetics, autoimmune disease or traction will not necessarily improve simply by taking vitamins.

Should I worry about a bald patch?

A new bald patch should be assessed because patchy hair loss has several possible causes, including alopecia areata and certain scalp conditions.

The Bottom Line

If you're asking “Why is my hair falling out?”, first distinguish between ordinary shedding and a genuine change in your hair.

Losing some hair every day is normal.

But increased shedding or thinning can occur after stress, illness, rapid weight loss, iron deficiency, thyroid problems, hormonal changes or certain medications. Genetics can cause male or female pattern hair loss, while autoimmune conditions such as alopecia areata can cause distinct bald patches.

Your hair-care practices matter too. Repeatedly pulling the hair with tight braids, extensions or similar styles can damage follicles.

Most importantly, the treatment depends on the cause.

Rather than buying multiple oils, vitamins or expensive hair-loss treatments without knowing what is happening, investigate persistent or significant hair loss properly.

Related Reading

• Why Am I Always Cold? 9 Possible Reasons You Feel Cold All the Time
• Why Am I Still Tired After 8 Hours of Sleep? 10 Possible Reasons
• Why Do I Bruise So Easily? 9 Possible Causes and When to Worry

Sources and Further Reading

• NHS — Hair loss
  
  
• American Academy of Dermatology — Hair Loss: Overview
  
  
• Cleveland Clinic — Why Is My Hair Falling Out?
  
  

Medical Disclaimer

This article is for general educational and informational purposes only and is not a substitute for professional medical advice, diagnosis or treatment. If you experience sudden, persistent or unexplained hair loss, bald patches or concerning scalp symptoms, consult an appropriately qualified healthcare professional.