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.
Causes of Otitis externa. Causes of Otitis externa. Otitis externa is caused by a bacterial or viral infection in the external part of the ear canal. A common bacterial pathogen is Pseudomonas aeruginosa. List of causes of Otitis externa. Otitis externa Causes: Risk Factors.
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.