Why Am I Losing My Eyelashes?

Losing eyelashes is more common than most people realize, and it rarely means something serious is happening. Eyelashes shed and regrow on a natural cycle, just like the hair on your head. When you notice more loss than usual, the cause is usually something specific and often temporary — an eye infection, a cosmetic habit, a thyroid issue, or a medication side effect. Identifying the pattern of loss is the first step toward understanding what is driving it.

Why Am I Losing My Eyelashes?

Eyelashes grow in a cycle with three phases. The growth phase (anagen) lasts roughly four to ten weeks. The transition phase (catagen) lasts about two to three weeks. The resting phase (telogen) lasts around three to four months, after which the lash falls out and a new one begins growing.

At any given time, different lashes are in different phases. That means some shedding every day is completely normal. The average person loses a few eyelashes daily without noticing. What matters is whether the loss is diffuse (spread across the lash line) or patchy (clumped in one area), and whether lashes are growing back.

When loss exceeds what the growth cycle would explain, something is disrupting that cycle. The most common culprits fall into a few categories: inflammation or infection of the eyelid, hormonal or autoimmune conditions, nutritional deficiencies, medications, and mechanical damage from cosmetics or extensions.

One detail worth understanding: eyelashes are different from scalp hair. They have a much shorter growth phase and a longer resting phase. This makes them more vulnerable to anything that pushes hairs prematurely into the resting phase, because a higher proportion of lashes are already near the end of their cycle at any given moment.

What Medical Conditions Cause Eyelash Loss?

Several conditions can cause eyelashes to thin or fall out. Some are common and easily treated. Others are chronic and require ongoing management.

Blepharitis is inflammation of the eyelid margins. It is one of the most frequent causes of eyelash loss. The eyelids become red, crusty, and irritated. Debris and inflammation at the base of the lashes can weaken them and cause them to fall out. Blepharitis is often associated with skin conditions like rosacea or seborrheic dermatitis. It is typically managed with eyelid hygiene, warm compresses, and sometimes prescription treatments.

Demodex infestation is related. Demodex are microscopic mites that live in hair follicles, including eyelash follicles. Nearly everyone has some, but overgrowth can cause inflammation, itching, and lash loss. This is diagnosed by an eye doctor and treated with specific eyelid cleansers or medications.

Alopecia areata is an autoimmune condition in which the immune system attacks hair follicles. It can cause patchy loss of eyelashes, eyebrows, and scalp hair. The loss is usually sudden and well-defined. Alopecia areata is not curable, but some treatments can help regrowth in certain cases. Results vary widely between individuals.

Thyroid disorders, particularly hypothyroidism, can cause diffuse hair loss including eyelashes. The mechanism involves disruption of the hair growth cycle. When thyroid levels are corrected with treatment, hair often regrows, though it can take several months.

Trichotillomania is a condition in which a person compulsively pulls out their own hair, including eyelashes. It is classified as a body-focused repetitive behavior. It is more common than many people realize and is treatable with behavioral therapy.

Can Makeup and Eyelash Extensions Damage Your Lashes?

Yes. Mechanical and chemical damage from cosmetics is one of the most overlooked causes of eyelash thinning.

Waterproof mascara is a frequent offender. It requires more rubbing and tugging to remove, and that friction pulls lashes out prematurely. Over time, repeated pulling can damage the follicle itself. Sleeping in mascara makes it worse, because the product hardens and can cause lashes to break or fall out during the night.

Eyelash extensions are another common cause. The adhesive used to attach extensions can irritate the eyelid margin and cause inflammation. The weight of the extensions can also pull on natural lashes. If extensions are applied improperly or removed incorrectly, natural lashes can come out with them. Some people develop allergic reactions to the cyanoacrylate adhesives used in extensions, which can cause eyelid swelling and lash loss.

Eyelash perming and tinting involve chemicals applied close to the eye. These can cause irritation and, in some cases, damage to the lashes themselves. Reactions to these products are not rare.

If you suspect your cosmetics are the cause, the most useful step is a break. Stop using extensions, waterproof mascara, and lash perms for several weeks. If lashes begin to grow back, the cause was likely mechanical or chemical.

Which Medications Can Cause Eyelash Loss?

Several classes of medications are associated with eyelash loss. This is not a complete list, but it covers the most commonly implicated drugs.

• Chemotherapy agents — many cause widespread hair loss including eyelashes. Loss typically begins weeks after treatment starts and regrowth usually occurs after treatment ends.
• Thyroid medications — in some cases, both hypothyroidism and its treatment can affect hair cycling.
• Anticoagulants and blood thinners — can contribute to hair shedding in some people.
• Retinoids — oral isotretinoin and similar drugs are associated with hair thinning.
• Beta-blockers — some people experience hair loss while taking these.
• Anticonvulsants — certain seizure medications have been linked to hair loss.

The relationship between a medication and eyelash loss is not always straightforward. Hair loss can begin weeks or months after starting a drug, making the connection easy to miss. If you suspect a medication is involved, do not stop taking it on your own. Talk to your prescribing doctor about whether an alternative exists.

Can Nutritional Deficiencies Cause Eyelash Loss?

Nutritional deficiencies can contribute to hair loss, though they are less commonly the sole cause of eyelash loss specifically.

Iron deficiency is one of the most well-established nutritional causes of hair shedding. Ferritin levels below the normal range have been associated with increased hair loss in some studies. The evidence is stronger for scalp hair than for eyelashes specifically, but the mechanism is the same.

Zinc deficiency can cause hair loss, including eyelash loss. Zinc is involved in hair follicle function and protein synthesis. Severe zinc deficiency is rare in the US, but mild deficiency can occur with certain diets or medical conditions.

Biotin deficiency is often cited as a cause of eyelash loss, but true biotin deficiency is rare. Most people get enough biotin from their diet. There is no strong evidence that biotin supplements help eyelash growth in people who are not deficient. Some research suggests biotin supplements can interfere with certain lab tests, including thyroid and cardiac tests, which is worth knowing before starting them.

Vitamin D has been studied in relation to hair loss, but the evidence is mixed. Some studies show an association between low vitamin D and alopecia areata, but it is not clear whether low vitamin D causes the condition or is a result of it.

If you suspect a nutritional deficiency, a blood test is the right first step. Taking supplements without knowing whether you are deficient is unlikely to help and can occasionally cause harm.

When Should You See a Doctor About Eyelash Loss?

See a doctor if the loss is patchy rather than diffuse, if it is accompanied by eyelid redness, swelling, or crusting, or if lashes are not growing back after several months.

Also see a doctor if you notice other symptoms alongside the lash loss — unexplained weight changes, fatigue, skin changes, or hair loss elsewhere on the body. These can point to a systemic cause like a thyroid disorder or an autoimmune condition.

An eye doctor (ophthalmologist or optometrist) can examine the eyelid margin and lash follicles directly. In some cases, a skin biopsy or blood tests may be needed. The evaluation is usually straightforward and non-invasive.

One clarification: eyelash loss on its own, without other symptoms, is rarely a sign of something dangerous. But it can be a sign of something treatable. Getting an accurate diagnosis is worth the effort.