Ingrown toenails is a painful condition that occur when the edges or corners of the nails grow into the skin next to the nail. The big toe is most likely to get an ingrown toenail. Various causes include poorly fit (tight) footwear, infection, improperly trimmed toenails, trauma, and heredity. The great toe is the most commonly involved, the lateral side involved in more cases than the medial side. The affected toe has all the classic signs of infection such as pain, edema, erythema, and warmth. If an ingrown nail is left untreated, there exists a high risk of dangerous infection. The mechanism of how and why this infection occurs is as follows: When the skin around the nail gets infected, it begins to swell up and put even more pressure against the nail. Ingrown nails can produce a spear shaped wedge of nail on the lateral side of the toe which will progressively become more embedded into the toe tissue as the nail grows forward. In the worst case, the swelling will begin putting sideways pressure on the nail, causing it to grow at a slant. This will cause both sides of the nail to eventually become ingrown and swollen. Eventually the swollen parts of the skin will begin to harden and fold over the nail. The initial surgical approach is typically a partial avulsion of the nail plate known as a wedge resection or a complete removal of the toenail. If the ingrown toenail reoccurs despite this treatment, destruction of the germinal matrix with phenol is recommended. In a wedge resection, seen above, the digit is first injected with a local anesthetic. When the area is numb, the physician will perform an onychectomy in which the nail along the edge that is growing into the skin is cut away (ablated) and the offending piece of nail is pulled out.