The sudden thinning or loss of eyelashes can be an alarming change, but it is often a symptom of an underlying issue rather than a standalone disease. The medical term for the loss of eyelashes, whether partial or complete, is called ciliary madarosis. While losing a few lashes daily is a natural part of the hair growth cycle, significant or patchy loss signals that the hair follicles are being damaged or disrupted. Understanding the typical life cycle of a lash helps differentiate normal shedding from loss requiring attention.
The Natural Eyelash Hair Cycle
Eyelashes, like all hair on the human body, follow a predictable three-phase growth process before they naturally shed. The first stage is the Anagen phase, which is the active growth period lasting approximately 30 to 45 days. During this time, the lash actively grows to its genetically determined length.
Next is the Catagen phase, a short transitional stage where the hair follicle shrinks and growth ceases. This phase lasts for about two to three weeks as the lash prepares to shed. Finally, the Telogen phase is the resting stage, which can last for over 100 days before the old lash is released and the cycle restarts with a new hair growing underneath. Because each lash is on its own schedule, you typically shed only about one to five lashes per eye each day.
External Factors and Cosmetic Practices
Many instances of eyelash loss are directly related to mechanical stress or chemical irritation that prematurely interrupt the natural growth cycle. One common cause is traction alopecia, a condition resulting from constant, prolonged tension on the hair follicle. This is frequently seen with the use of eyelash extensions that are too heavy for the natural lash or when extensions are applied improperly, gluing multiple natural lashes together.
Improper removal or aggressive rubbing of the eyes, often due to chronic itchiness or while removing stubborn makeup, physically pulls the lash out before the Telogen phase is complete. This mechanical trauma can damage the follicle, causing the new lash to take longer to regrow, or in severe cases, cause permanent damage. Chemical exposure from cosmetics can also be problematic, especially the formaldehyde-based adhesives used for extensions, which can cause an allergic reaction.
Poor eyelid hygiene can lead to blepharitis, a chronic inflammation of the eyelid margin often caused by clogged oil glands or an overgrowth of bacteria or microscopic mites. The chronic irritation and inflammation associated with blepharitis weakens the lash follicles over time, leading to thinning and loss. Certain topical eye medications, such as those used to treat glaucoma, can also have a temporary side effect of lash loss when use is discontinued.
Underlying Health Conditions
When eyelash loss is sudden, bilateral, or not explained by cosmetic routines, it may be a symptom of a systemic health issue requiring medical evaluation. Endocrine disorders, particularly thyroid dysfunction, are a frequent medical cause of generalized hair loss, including the eyelashes. Both an underactive thyroid (hypothyroidism) and an overactive thyroid (hyperthyroidism) can disrupt the body’s metabolism and affect the hair growth cycle.
Autoimmune conditions can also target and damage the hair follicles, leading to loss. Alopecia Areata is an autoimmune disease where the immune system mistakenly attacks the hair follicles, sometimes resulting in patchy or complete loss of eyelashes. Other chronic inflammatory diseases like Systemic Lupus Erythematosus (SLE) can affect the skin around the eyelids, causing inflammation that damages the follicles.
Certain oral medications can also induce temporary hair loss, a known side effect of systemic treatment. This includes chemotherapy drugs, which target rapidly dividing cells, but also some prescription drugs used for conditions like arthritis or acne. If eyelash loss is accompanied by other systemic symptoms such as fatigue or unexplained weight changes, it is advisable to consult a healthcare provider for a definitive diagnosis.