In most cases ingrown toenails are happening only to your toes but also there are some cases in which fingernails can be also ingrown. They occur less frequently in fingers because you are not squeezing your fingers into shoes that do not fit well. Also the shape of our fingernails makes them less likely that they will become ingrown. But ingrown fingernails can happen and they can become infected. This can make your everyday tasks painful such as when you wash dishes or when you type on a keyboard. 
The most common symptoms of ingrown toenails are
- Bulge beneath the skin
- Pus around the skin
- Sensitive skin
Causes: Long nails, sharp nail edges, nail deformity, curved nail shapes, nail biting and poor nail maintenance are the most common causes of ingrown fingernails. Also in many cases the incorrect trimming and cutting of nails lead to ingrown nails.
Ingrown toenails: An ingrown toenail is a toenail which has grown into your skin instead of over it. This is a common condition in which the side or corner of a toenail grows into the soft flesh. The result is a swelling, redness, pain and in some cases an infection. In the most cases the big toe is affected by ingrown nails. In many cases you can take care of your ingrown toenails on your own. If the pain is spreading or severe, then you should ask your doctor about the best treatment which can give you a relief from the discomfort and also it will help you to avoid complications of ingrown toenails. If you suffer from diabetes or another condition which causes poor blood to your feet, then you have increased risk of complications of ingrown toenails.
The most common symptoms of ingrown toenails are:
- Infection of the tissue around your toenail
- Swelling of your toe around the nail
- Redness around your toenail
- White or yellow pus coming from the affected area
- Pain and tenderness in your toe along one or both sides of the nail
- A build-up of fluid in the area surrounding the toe
- Inflammation of the skin at the end of the toe
- An overgrowth of skin around the affected toe
If you experience severe discomfort in your toe or if you have a pus or redness that seems to be spreading, then you need to talk with your doctor. Also if you suffer from diabetes or another condition which causes poor blood flow to your feet and you experience any foot infection or sore, then you need to ask for medical help. Your doctor will make a physical exam to diagnose an ingrown toenail. Your doctor will look at your toe where the nail has grown into your skin. You should always trim your toenails straight across. You should not curve your nails to match the shape of the front of your toe.
Causes of ingrown toenail
The big toe is often affected, either on one or both sides. There are many different causes which can lead to ingrown toenail. Rounding the edge of your nail or cutting your toenail too short can cause it to grow into your skin. When you wear socks or shoes which do not fit well, they can also lead to ingrown toenails. If your shoes are too tight, then they can press your nail into your toe and this can cause it to grow into your skin. Also when you hurt your toe, such as stubbing your toe, then you can also get an ingrown toenail. This can lead to your nail to grow inward. Also when you repeat some activities such as kicking a soccer ball, then this can also lead to ingrown nail. 
- Genetic predisposition 
- Improper foot hygiene, such as not keeping your feet clean or dry 
- Poor posture 
- Toenail injury, including stubbing your toe, dropping something heavy on your foot or kicking a ball
- Footwear that places a lot of pressure on the big toes, such as socks and stockings that are too tight or shoes that are too tight, narrow or flat for your feet 
- Irregular, curved toenails 
- Cutting toenails incorrectly (cut straight across, since aging the sides of the nail can encourage the nail to grow into the skin) 
Above are the most common causes for ingrown toenails.
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