According to the WebMD, The first reason shows the symptoms of various serious diseases like thyroid disease, psoriasis and also fungal infection, which is why if you find your nails yellow, you are required to consult a doctor about it. Whereas the second reason is nothing to talk about as it could be due to the nail polish stain and for which you do not need to concern. If you find your nails green, you may face GNS (Green Nail Syndrome). People who work in healthcare and as a cook, seems to have more risk of getting this disease. According to “American Osteopathic College of Dermatology “ this disease is caused by the harmful bacteria named Pseudomonas Aeruginosa. If you find your nail colour as blue, then it may be caused due to the cold temperature and or it may also a symptom of cyanosis. In this disease, the RBC’s are found to be in lack of oxygen.
2. Unusual shapes and structures may be caused due to the nutritional deficiency
Onychogryphosis, a condition where nails start growing into unwanted shapes and structures. This condition can be caused due to the diseases like psoriasis or hystrix. A podiatrist may help you get out of it, while sometimes, removing the nail is all solution.
According to Mayo Clinic, if you find the ridges of nails in the vertical direction, then it may be a normal process of nail growth, although sometimes, they get thicker, due to the increase in person’s age.
While according to the institute “Harvard Health Publishing”, if you find the ridges if your nails in the horizontal direction, then it may due to the lack of proper nutrients. When our body doesn’t get the proper nutrients, then also it may badly effect to our nails.