The Complete Guide to Nail Health: In-Depth Analysis of Abnormal Color, Texture, and Shape

A bluish tinge to the lunula (the white crescent-shaped area at the base of the nail) may indicate heart disease, Raynaud's disease, or impaired blood circulation. Vasospasm in the fingers and toes is usually caused by cold exposure, but can sometimes be associated with rheumatoid arthritis or autoimmune diseases such as lupus. A bluish lunula suggests respiratory problems and a predisposition to cardiovascular disease; a reddish lunula corresponds to heart failure. A pink or brown half of the nail near the tip and a white half near the nail root may be a sign of chronic kidney failure. Abnormal nail colors also have different meanings: an abnormally red or dark reddish little fingernail indicates endocrine problems. Dark red or bluish-purple nails indicate cardiovascular disease and poor blood circulation. If most of the skin under the nail turns white, with only a small portion near the tip remaining pink, this may indicate cirrhosis. Pale nails indicate weakness and anemia; sudden whitening of the nails often indicates acute conditions such as blood loss or shock, or chronic diseases such as hookworm disease, gastrointestinal bleeding, or late-stage tuberculosis. Slowed nail growth, thickening and hardening, and a yellowish-green color are commonly seen in respiratory, lymphatic, thyroid, jaundice, and hepatitis diseases. Gray nails are often caused by oxygen deficiency and are more common in smokers; a sudden graying of the nails is most likely due to onychomycosis (nail fungus). People with cirrhosis, kidney failure, or uremia have reduced albumin production, resulting in nails that are purplish-brown at the tips and white at the ends. Yellowing nails are common in vitamin E deficiency, hypothyroidism, carotenemia, and nephrotic syndrome. Partially shiny nails are often related to pleurisy and ascites; shiny nails throughout are common in hyperthyroidism, diabetes, and patients with acute infectious diseases. If each nail has a shiny tip but a rough, dull base, it may indicate chronic bronchitis and cholecystitis. An unusually dull thumbnail color may indicate heart problems. Black spots on the nail bed may be caused by bacterial endocarditis; a few white spots on the nails usually indicate calcium or silicon deficiency or parasitic infections. Changes in nail ridges and shape can indicate: Horizontal grooves on the nails may indicate malnutrition or a serious illness that temporarily affects nail growth, such as measles, mumps, or a sudden heart attack. A rough nail surface with vertical ridges often appears due to overwork, mental strain, or lack of sleep; these ridges become more prominent. Persistent vertical ridges may indicate chronic organ disease. Longitudinal red lines on the nails indicate microvascular bleeding; multiple such lines may suggest chronic hypertension or psoriasis. A nail that is concave in the middle, becoming flat or spoon-shaped, is associated with iron-deficiency anemia, syphilis, thyroid dysfunction, and rheumatic fever. Rows of pits on the nail surface can sometimes be caused by alopecia areata.