Ridges in nails are quite common and may have not specific cause except genetics. However, there are other conditions that can cause fingernail ridges and may be something to worry about, especially when other symptoms manifest as well.
Genetics and Age
Sometimes, fingernails are shaped and formed in a certain way that makes it easy for ridges to appear. The trait can be hereditary and they are generally slight, often barely noticeable. Many people notice ridges appearing on the same digits as parents or siblings. Ageing can also cause the appearance of ridges in the nails.
Ridged nails are a common symptom of malnutrition or malabsorption. When the body doesn't receive certain vitamins, the internal processes that create fingernails are interrupted, creating the ridges. Sometimes the cause of malnutrition is a poor diet, but it could also be a problem with the way the body absorbs nutrients. There are certain diseases and conditions that block the absorption of certain vitamins and minerals.
When nails get cracked and dry, ridges can form. When the nail area doesn't receive enough moisture, either from within or externally, the normal production process is halted. Drinking plenty of water and applying moisturizers to the hands can greatly reduce the appearance of ridges in nails that are caused by dryness.
Certain diseases can affect the nails, including creating ridges and discoloration. Respiratory and circulatory problems can manifest in the nails as can certain toxic conditions such as poisoning. Even something as common as the flu can result in fingernail lines for a short time. Lengthwise fingernail ridges are often noted as a symptom of kidney failure or an iron deficiency. It can even be a precursor to arthritis.
Nail ridges can be accompanied by a few other symptoms that combine to signal health concerns. When pits in the nails accompany ridges, it may be a clue that the patient has psoriasis, a serious skin condition. When the fingernail lines run across the nail, diabetes or circulatory diseases may be the culprits.