Demodex refers to microscopic parasitic mites that naturally inhabit human hair follicles and sebaceous (oil) glands, particularly on the face, eyelashes, and scalp. The two species most commonly found in humans, Demodex folliculorum and Demodex brevis, are usually harmless and present in small numbers without causing symptoms. However, overgrowth can contribute to skin conditions such as rosacea, blepharitis (eyelid inflammation), itching, redness, and irritation. Factors such as weakened immunity, increased oil production, aging, or poor skin hygiene may promote higher mite populations. Diagnosis is typically made through microscopic examination of skin scrapings or eyelashes, and treatment may involve medicated cleansers, topical antiparasitic agents, or therapies aimed at reducing inflammation and controlling underlying skin disorders.