If you have linear ridges, known in the medical world as Beau's Lines, your nails are trying to tell you something. You may be vitamin or mineral deficient (lack of zinc can cause the ridges), it could be a bad allergic reaction to a new polish, or something more serious, like diabetes. "Beau's Lines can be associated with anything that stresses the body and requires it to divert resources away from nail growth," says Steele. "This could be anything from a surgery, to severe illness, or a reaction to certain medications." Don't rush to WebMD to diagnose yourself; make an appointment with your doctor to find out of this is a minor reaction or a major health concern.

If your nail folds are red, swollen, and tender, chances are you have an infection, According to Steele, puffy nail folds tend to occur with a condition called paronychia, but don't let the big name scare you. Paronychia is a skin infection that occurs around the nails and is fairly common. It can be caused by a bacterial or fungal infection from everyday trauma and inflammation — think: nervously gnawing your cuticles, picking a hangnail, or simply over-washing your hands.

Clubbed nails are hard to miss, and they are not to be taken lightly — this nail condition can signal a serious illness, says Steele. "Clubbing of the nails is typically a sign of long-standing or severe cardiovascular or lung disease and poor oxygenation," says Steele. And the list only goes on — clubbed nails can also signal cyanotic congenital heart disease, cystic fibrosis, and chronic inflammatory bowel disease. All of these diseases cause the small arteries in the fingertips to dilate, which enlarges the tissues of the nail beds and causes the fingernails to club.

If your nails are more concave than clubbed, you may have a condition called koilonychias, or spoon nails. "Spoon nails can be associated with iron deficiency to the point of anemia, but it is usually a rare association," says Steele. "Most people with spoon nails do not have an underlying cause, but it is worth getting evaluated to make sure iron and blood counts are normal."

If your nails are separating from your cuticle, think of this as more of a side effect than a warning symptom. It could be onycholysis, a condition that happens when the nail separates from the nail plate due to trauma, says Steele. "I.e. someone inserting something beneath their nail plate in order to 'dig' something out or clean under it," says Steele. Onychomaedesis is the term for your nail separating from the cuticle. "This can occur after a systemic illness (viral infection, cold, etc.). The nail plate usually sheds and then a new nail grows out," says Steele. So stay away from rough manicures and let your body rest.