Possible causes:
Severe trauma or infection.
Major nutritional deficiency.
Underlying diseases such as diabetes, cardiovascular or respiratory disorders.
When to consult?
If these streaks are present on all nails, they could signal a systemic disease such as pneumonia, syphilis, or Kawasaki disease.
White streaks: indicators of liver and kidney health
Parallel white lines without altering the texture of the nail could reveal liver or kidney problems. These marks, called Muehrcke lines, appear when blood protein levels are low.
They may indicate:
Chronic liver disease.
Renal failure.
Severe malnutrition.
What to do?
If these lines are visible on several nails and disappear under pressure, a medical consultation with a blood test is recommended.
