Porphyrins are by-products of heme synthesis that are normally present at low levels in blood and other body fluids. Lab tests measure porphyrins and their precursors in urine, blood, and/or stool to help diagnose porphyrias, including neurologic porphyrias and cutaneous porphyrias.
Osmolality measures the amount of dissolved substances (e.g., sodium, potassium) in blood and urine. An osmolality test and calculated osmolal gap help determine if someone has ingested a toxin or has a water imbalance.
Nicotine and cotinine tests detect evidence of nicotine in the body. Learn more about when these tests may be used and how to understand your test results.
Myoglobin is a small, oxygen-binding protein found in heart and skeletal muscles. When heart or skeletal muscle is injured, myoglobin is released into the blood and eliminated from the body in the urine. A myoglobin blood test may be used to detect muscle damage and a myoglobin urine test may reflect muscle damage and risk of kidney damage.
Mycoplasma tests are used to detect an active or recent mycoplasma infection caused by Ureaplasma urealyticum or Mycoplasma hominis, bacterias transmitted through sexual contact.
The MTHFR mutation test may sometimes be ordered when a person has elevated homocysteine levels, especially when the person has a personal or family history of premature cardiovascular disease or thrombosis.
