Eyelash shedding is a fundamental part of the body’s natural hair renewal process. Like hair on the rest of the body, eyelashes follow a predictable cycle of growth and rest. This means some level of daily loss is a normal biological occurrence, and understanding this cycle helps distinguish routine shedding from a potential underlying problem.
The Natural Eyelash Growth Cycle
Eyelashes, or cilia, grow in a repeating sequence known as the hair growth cycle, which is divided into three distinct phases.
Anagen Phase
The anagen phase is the active period of growth, typically lasting between 30 and 45 days. During this time, the cells at the root of the lash are rapidly dividing to build the hair shaft to its full length. Only about 40% of the upper lashes are in this active growth phase at any given moment.
Catagen Phase
Following the active growth is the catagen phase, a brief transition period lasting approximately two to three weeks. In this stage, the hair follicle begins to shrink and detaches from the dermal papilla, cutting off the blood supply. The eyelash stops growing, and if it falls out during this phase, the follicle will not immediately begin the next cycle.
Telogen Phase
The final stage is the telogen phase, a prolonged resting and shedding period that can last up to 100 days. The old lash simply rests in the follicle before naturally detaching and falling out to make room for a new lash. This natural shedding ensures that the lash line remains full and healthy over time.
Defining Normal Versus Excessive Eyelash Loss
It is considered normal to lose anywhere from one to five eyelashes per eye each day as they complete the telogen phase. This minimal amount of shedding is usually unnoticeable because the lash line contains hundreds of hairs, and new ones are always growing in to replace the lost ones.
Eyelash loss becomes excessive, a condition sometimes termed madarosis, when the shedding rate is noticeably higher than five lashes per day, leading to visible gaps or thinning along the lash line. Signs of excessive loss include finding small clumps of lashes, experiencing loss that is sudden, or observing patchiness on both the upper and lower eyelids. When the rate of loss exceeds the rate of new growth, it signals an interruption that warrants attention.
Underlying Causes of Excessive Eyelash Loss
Excessive shedding can be grouped into external trauma, local eye conditions, or systemic health issues.
External Trauma
External factors often involve physical stress placed directly on the lashes and their follicles. This can include the improper use of harsh cosmetics, vigorous rubbing of the eyes, or the incorrect application and removal of eyelash extensions. A psychological condition known as trichotillomania, where a person compulsively pulls out their own hair, is also a traumatic cause of lash loss.
Local Eye Conditions
Local conditions affecting the eyelid margin are common contributors to excessive loss. Blepharitis, which is chronic inflammation of the eyelids, is a frequent culprit, often caused by bacterial overgrowth or clogged oil glands near the lash base. Infestation by Demodex mites, microscopic organisms that live in hair follicles, can also irritate the eyelid and lead to inflammation and subsequent lash loss.
Systemic Health Issues
Systemic health issues interrupt the hair cycle by diverting the body’s resources away from non-essential functions like hair growth. Thyroid disorders, specifically both hypothyroidism and hyperthyroidism, are known to affect overall hair health. Autoimmune conditions like alopecia areata prompt the immune system to attack hair follicles, causing hair loss on the scalp, eyebrows, and eyelashes. Furthermore, significant nutrient deficiencies (such as low iron, zinc, or biotin) or periods of high physical or emotional stress can push lashes prematurely into the resting and shedding phase.
When to Consult a Healthcare Professional
If you notice a sudden, rapid increase in eyelash loss, it is advisable to consult a healthcare provider for an evaluation. Medical attention is warranted if the loss is accompanied by other concerning symptoms, as this may indicate an underlying health issue.
Specific red flags include loss that is asymmetrical or occurs alongside noticeable thinning of the hair on the eyebrows or scalp. You should also seek professional advice if you experience local symptoms such as pain, persistent itching, burning, redness, or scaling of the eyelid skin. Loss associated with any non-healing sores or growths on the eyelid also requires immediate medical examination.