The ischemic forearm exercise test is a diagnostic procedure that tests for possible metabolic causes of muscle weakness, cramps and fatigue. After the patient rests fully for 30 minutes, a blood pressure monitor is placed on their upper arm and they are set up with an intravenous line with saline and heparin. A blood sample is taken for reference purposes. The blood pressure cuff is then inflated and the patient is then given the squeeze bulb and is required to squeeze it themselves every two seconds for a period of two minutes, making sure that their fingers are fully extended between squeezes. After they are finished, the cuff is deflated and blood samples are taken 1, 3, 7 and 9 minutes later.