The cause of muscle cramps isn't always known. Muscle cramps may be brought on by many conditions or activities, such as: 1  Exercising, injury, or overuse of muscles. 2  Pregnancy. 3  Cramps may occur because of decreased amounts of minerals, such as calcium and magnesium, especially in the later months of pregnancy.
Putting fingers, cotton swabs or other objects in your ears also can lead to swimmer's ear by damaging the thin layer of skin lining your ear canal. Swimmer's ear is also known as otitis externa. The most common cause of this infection is bacteria invading the skin inside your ear canal. Usually you can treat swimmer's ear with eardrops. Prompt treatment can help prevent complications and more-serious infections.
The causes of otitis externa, or swimmerâs ear, as the name suggests, include swimming or other situations in which water remains in the ear, creating a warm, moist environment that encourages the growth of bacteria. In addition, the water itself might be contaminated with bacteria or other organisms.ater from other sources, such as showering, can remain in the ear and cause problems. Otitis externa can be also be the result of an infection of the bone at the base of the skull, a foreign object lodged in the ear, and irritation from itching or cleaning the ear.