Chinese physicians use fingernail condition to accurately diagnose many medical problems. They believe that changes in nails can signify a variety of disorders anywhere in the body, often before other signs or symptoms appear. Like acupuncture, this has been common practise for thousands of years. An ancient Chinese medical text claims: If something happens in the interior of the body, it must be reflected in the exterior of the body.
Common Colours and Conditions
There are a range of colours in nails that may denote health problems. They ought not be ignored. Here are some of the more common ones:
- Bluish/deep blue nail beds – heart or respiratory problems/pulmonaryobstruction/asthma/emphysema
- Dark blue line in nail – can be sign of skin cancer
- White/pale/lacking lustre – can indicate anaemia/lack of vitality or liver/kidney disorders
- White/waxy – may mean internal bleeding or worm infestation
- White nails with pink near tips – may be sign of cirrhosis
- White/crumbly – often fungal infection
- Nail half white/dark spots on tips – possible kidney disease
- Yellow – may be the first warning of major illness, eg respiratory, liver, lymphatic systems/diabetes/cancers. Can also be found in any condition that causes nail growth to slow down
- Yellow and thick—common in smokers/ possible fungus/ potential pulmonary disease.
- Pink half moons – may signify candida infection
- Light red left index fingernail – may mean high blood pressure
- Light red or purplish – may indicate prostate problems
- Dark nails – vitamin B 12 deficiency/anaemia
- Brown strips in upper third of nail (or whole of upper nail goes brown) when kidneys are damaged.
- Greenish nails – sign of infection
- Greyish nail roots – chlorine deficiency
- Irregular red lines at base of the nail fold – possible lupus or connective tissue disease
- Dark line or streak under the nail – always have checked for melanoma (especially if under nail of thumb or big toe)
- Tiny black streaks – can mean heart disease
- Reddish, brown spots – deficiencies (folic acid, vitamin C, protein)
- Opaque nails with dark band at top – can be simply ageing but check for more serious conditions (heart/liver/diabetes/cancer)
Marks on nails can also be important signs of a health problem. Here are a few to look out for:
- Small white spots under nails – deficiency zinc or calcium/worms/chronic constipation/fatigue/ virus in adolescence/fasting
- Single horizontal white line – lead/arsenic poisoning
- White lines across nail may denote liver disease/heart disease/fever
- Horizontal ridges – may indicate stress or be a sign of the flu/other infections/gastrointestinal troubles.
- Vertical ridges are common in many conditions eg fibromyalgia/calcium deficiency/anaemia/digestive weakness/kidney problems/parasites. They are also more common in ageing and those with tendency to arthritis
- Vertical black lines at the top of the thumbnail may indicate heavy metal toxicity.
- Pitting – psoriasis/psoriatic arthritis/dermatitis/or associated with alopecia (hair loss)
Grooves and Moons
Grooves in nails and moons (crescents or arcs at base of nail) also give us clues to overall health:
- Horizontal grooves/dips – present after recent physical or emotional health problem/parasites (see also depression in nails)
- Groove in index fingernail – may mean tendency towards skin disease
- Groove in ring fingernail – possible eye problems
- Groove in middle fingernail – loss of muscle strength
- Well shaped moons – indicate good health/good cardiovascular function
- Unusually large or asymmetrical moons – possible high blood pressure
- Lack of moons – may mean problems with nervous system
- Small/obscured moons – asthma/gout/respiratory or gastrointestinal problems
- Low moons on thumbs – may not be absorbing minerals
- Moons are often obscured after a stroke
- Red moons – can indicate heart problems
- Slate blue moons – overexposure to silver/or lung problems
- Should have moons on all except little fingers. If on little ones, check for heart disease
Shapes and Other Nail Conditions
All of these are important to look out for, as often early signs of health problems:
- Flat nails– indicate lowered resistance to disease/physical weakness/Raynaud’s Disease
- Clubbed ends of fingers/nails – lung disease/emphysema, bronchiectasis, etc.
- Peeling top layers of nail indicate liver weakness
- Very thick nails – can indicate weakening vascular system/ or candida
- Cracked nails – may be deficient in silicon
- Brittle nails – possible iron, zinc, biotin or calcium deficiency/thyroid problems/ kidney or circulation problems/or low in essential fatty acids. Can also be caused by contraceptive pill.
- Flaking nails – low in essential fatty acids
- Splitting nails – can be early sign of psoriasis or thyroid problems
- Thinning nails – may involve skin disease (itching)
- Red skin at the base of the nail – possible connective tissue disorder.
- Nails curving downward – possible heart/liver/respiratory disease/vitamin B12 deficiency (low B12 can be associated with curving up or down)
- Nails curving upward (spoon shaped) – vitamin B 12, iron or chromium deficiency/anaemia/scurvy
- Depression in nails usually marks period of ill health or crash diet. Can take months to grow out.
- Raggedy cuticles – lack of calcium
- Nails separating from nail bed – can be reaction to nail polishes/drug reactions/thyroid/or fungal disease
- Nails can be a window to out health status. They can warn us early of impending problems. If nails are healthy, smooth and pink with a slightly curved surface, you are probably pretty healthy too, but nails that are unhealthy, brittle, discoloured, misshapen, may mean you have a nutritional deficiency or some other health problem
People who wear artificial nails or use nail polish should remove it often and check for any unusual changes in their nails. Nails provide us with early warnings of problems. Masking or ignoring those signs is not good for health.
Disclaimer: This information is not meant to replace proper medical care. Always have anything unusual checked by your doctor. Any obvious changes in fingernails or toenails ought to be discussed with your doctor or podiatrist.
Scheinfeld, Noah, Vitamins and minerals : Their role in nail health and disease,
Department of Dermatology, Columbia University Presbyterian Hospital, New York,
Pfeiffer, C.C, Fingernail White Spots: possible Zinc Deficiency, JAMA, 1974
Yellow Nail Syndrome
Iqbal, M, chestjournal.chestpubs.org/content/117/5/1516.abstract, 2000
Common disorders and diseases of the nails. Anatomy, physiology, disorders, clarification and therapy
Pappert, AS, Longitudinal Pigmented Nail Bands, Dermatol Clin. 1991 Oct;9(4):703-16.www.ncbi.nlm.nih.gov/pubmed/1934645