If you have certain medical symptom such as hypertension, diabetes, rapid or irregular heart beats, and so on, your doctor may request that you take a stress test. Normal heart test such as listening through a stethoscope, taking heart beat and blood pressure, etcetera, cannot detect many heart problems. The reason is that most of these test are given while the patient is at rest. Many problems of the heart and circulatory system only manifest themselves when under stress.

Cardiac stress tests are normally only given to patients meeting certain heart risk criteria. These criteria would be those patients who are most at risk for coronary problems. This includes those with hypertension, diabetes, patients with a family history of heart problems, people who smoke or are overweight are all potential candidates having a cardiac stress test prescribed by their doctor. Also, anyone who has ever had a heart operation, will probably have follow-up cardiac stress tests as well. Should you take one or not? Only your doctor can best determine whether it's a good idea for you.

A special type of cardiac stress test is the thallium stress test. A thallium stress test makes use of a scintillation scan to measure the functionality of the heart. A scintillation scan uses a gamma camera for recording and an intravenously administered radioisotope, thallium-201, to highlight the affected areas of the heart muscle. This allows a physician to pinpoint very accurately the areas of the heart which might not be performing normally. The additional information gained by such a scan is vast. It shows heart muscle scarring, coronary blockages, lung circulation - just about everything the doctor needs to know to determine if any potential problems are on the horizon.

Even though of most use when a patient is exercising, a scintillation scan can be administered while the patient is at rest as well. When used as the patient is exercising, it can spotlight the heart compressions and expansions allowing the doctor to see, in real time, which areas of the coronary arteries might not be receiving enough oxygen.

A normal stress test starts by having the patient hooked up to an electrocardiogram machine. The patient may ride a bike or walk on a treadmill. The symptoms monitored for are - changes in blood pressure, breathing rate, and heartbeat rate. The technician will also be on the lookout for signs of angina, or chest pain, as well as irregular heart beats. As the test progresses, the incline of the machine will be slowly raised to force the patient to work a little harder. The stress test will normally last between 15 and 20 minutes - enough time to collect all the pertinent data that the doctor may be interested in.

The blood pressure and heartbeat rate will be measured before and after the stress test as well as the amount of time it takes for both markers to return to their resting rate.

It's worth noticing, however, that cardiac stress test are not 100% fail proof and just because you "flunk" the test, does not indicate that you positively have heart problems. About one out of every ten patients falsely test positive for heart problems. That's why, if the test shows that you have problems, you may be asked to take the test again.