Why Is My Hair Falling Out? Common Causes Explained

In Short:

• Losing around 100 hairs a day is generally completely normal; noticeably more than that is usually a sign that something has shifted.
• The most common causes include stress-related shedding, hormonal changes, nutrient gaps, and damaging hair habits.
• Identifying the root cause is the fastest path to figuring out what will actually help.

Noticing more hair than usual coming out onto your brush can be unnerving, and we’re here with some science-backed answers for you. Here’s a quick rundown of the most common reasons hair falls out and what you can do about it.

What Are the Most Common Causes of Hair Falling Out?

Hair falling out can result from a variety of different factors, or a combination of several. Here are some of the main contributors to hair loss.

Stress-Related Shedding (Telogen Effluvium)

A major physical or emotional stressor can push a large share of hair follicles into a resting phase at once, causing noticeable shedding a few months later.

This condition, called telogen effluvium, is one of the most common causes of sudden, diffuse hair loss . Illness, high fever, major life stress, surgery, and rapid weight loss can all trigger it. The good news is that it's usually temporary and resolves once the underlying stressor is addressed.

Hormonal Changes

Hormonal shifts from pregnancy, postpartum recovery, starting or stopping birth control, or thyroid changes can all trigger hair shedding.

Estrogen plays a significant role in keeping hair in its growth phase, so when levels fluctuate, more follicles shift into shedding mode. Thyroid hormone also plays a direct role in hair follicle health, and both an overactive and underactive thyroid can contribute to hair loss when the condition is more significant or long-lasting.

Nutrient Deficiencies and Crash Dieting

Not eating enough overall, or missing key nutrients like protein, iron, and zinc, can directly affect hair growth.

Hair is metabolically demanding to produce, so when your body isn’t getting enough calories or specific nutrients, it deprioritizes hair growth in favor of more essential functions. Highly restrictive diets low in amino acids, B12, iron, and zinc have been linked to increased hair shedding .

Damaging Hair Habits

Tight hairstyles, frequent heat styling, and being rough with wet hair can all contribute to hair breakage and thinning over time.

Tight braids, ponytails, and extensions can cause a type of hair loss called traction alopecia, where constant tension damages the follicle. Heat-styling tools and over- or under-washing your hair can also take a toll. Hair is especially fragile when wet, so gentle handling matters more than you might think.

Genetics

A genetic predisposition to hair thinning, often called pattern hair loss, is one of the most common long-term causes for both women and men.

This type of thinning tends to show up gradually, often starting with a widening part or thinning at the crown, rather than sudden shedding. Genetics influence how sensitive your hair follicles are to hormonal changes over time.

Underlying Health Conditions

Some autoimmune and scalp conditions can cause more significant hair loss and are worth having evaluated by a professional.

Conditions like alopecia areata, where the immune system affects hair follicles, can cause more noticeable patchy hair loss. If you’re experiencing sudden, patchy, or severe shedding, it’s worth checking in with a dermatologist to rule out an underlying condition.

The Takeaway

Hair falling out can feel alarming, but in most cases, it's tied to an identifiable, often temporary cause, whether that's stress, hormones, nutrition, or everyday hair habits. Understanding what's behind your specific shedding is the first step toward addressing it.

If you're not sure what's behind your specific hair changes, our two-minute hair quiz can help point you toward a root cause and the right next step. For ongoing support, our IFP-131™ Hair Growth Peptides  are formulated with our patented, clinically studied peptide complex to support visibly thicker, stronger hair over time.

Frequently Asked Questions

Is it normal to lose hair every day?

Yes. Losing up to around 100 hairs a day is a normal part of the hair growth cycle and isn't cause for concern on its own.

Can hair loss from stress grow back?

In most cases, yes. Stress-related shedding is usually temporary and resolves once the underlying stressor is addressed, though regrowth can take several months.

Why is my hair falling out even though I'm eating well?

Hair loss can have multiple causes at once, including hormonal shifts, genetics, or underlying health conditions, so good nutrition alone doesn't always rule out other contributing factors.

When should I worry about hair loss?

If you notice clumps of hair, bald patches, or shedding that continues for several months without improvement, it's a good idea to check in with a dermatologist.