In some cases, no cause can be found. Prevention is related to the cause. For example, excessive sweating due to exercise or hot weather can be avoided by avoiding activity or using air conditioning. Low blood sugar can often be avoided by getting enough to eat and taking medications to treat diabetes. Many cases of excessive sweating cannot be prevented.
Diagnosis starts with a history and physical exam.
This may be all that is needed in some cases to figure out the cause of the excessive sweating. In other cases, further testing may be needed. For example, thyroid function tests can detect increased thyroid hormone levels and a fasting blood glucose test can detect low blood sugar. A chest x-ray can often help diagnose pneumonia or tuberculosis . A special type of x-ray, called a cranial CT scan , can help diagnose a stroke .