Diesel Exhaust Fluid (DEF) is an emissions control liquid required by modern diesel engines. It is injected into the exhaust stream. DEF is never added to diesel fuel. It is a non-hazardous solution of 32.5% urea in 67.5% de-ionized water.
Side effects from cardiac stress testing may include. Palpitations, chest pain, myocardial infarction, shortness of breath, headache, nausea or fatigue. Adenosine and dipyridamole can cause mild hypotension. As the tracers used for this test are carcinogenic, frequent use of these tests carries a small risk of cancer.
1 Seventy-five percent to 90% of all doctor's office visits are for stress-related ailments and complaints.  Stress can play a part in problems such as headaches, high blood pressure, heart problems, diabetes, skin conditions, asthma, arthritis, depression, and anxiety.