Biofeedback therapy is a non-drug treatment in which patients learn to control bodily processes that are normally involuntary, such as muscle tension, blood pressure, or heart rate. It may help in a range of conditions, such as chronic pain, urinary incontinence, high blood pressure, tension headache, and migraine headache. As it is noninvasive and does not involve drugs, there is a low risk of undesirable side effects. This could make it suitable for those who wish to avoid medications, or those who cannot use them, such as during pregnancy. It is often combined with relaxation training.