Everyday Health Guide

A screening procedure for cervical cancer that collects cells from the cervix (the lower part of the uterus). It is best done when you are not on your period. Avoid intercourse, douching, or vaginal medications for 2 days before the test.

Measures PTH (a hormone produced by the parathyroid glands in the neck that regulates calcium and phosphorus levels in the body). Fasting may be required. A standard blood draw is performed.

Evaluates how well the blood clotting cascade (a series of steps that stop bleeding) is working. No fasting is required. A standard blood draw is performed.

A sterile needle is gently pricked into the skin of the forearm. The site is checked 24 to 48 hours later for an exaggerated inflammatory response (a red bump or pustule), which can indicate conditions like Behcet's disease.

Uses high-frequency sound waves to create images of organs in the lower abdomen, such as the uterus, ovaries, or bladder. For a transabdominal ultrasound, you may be asked to drink water and have a full bladder. A gel is applied, and a transducer (a device that sends and receives sound waves) is moved over the skin.

Measures phenylalanine (an amino acid found in protein) in the blood. High levels indicate phenylketonuria (PKU), a genetic disorder where the body cannot break down this amino acid. It is routinely done as a newborn screening via a heel prick.

Measures serum phosphorus (a mineral that works with calcium to build strong bones and teeth, and helps produce energy). Fasting may be required. A standard blood draw is performed.

Measures PlGF (a protein produced by the placenta during pregnancy). Low levels can indicate poor placental development and an increased risk of preeclampsia (a dangerous pregnancy condition involving high blood pressure). No fasting is required. A standard blood draw is performed.

Measures the number of platelets (tiny cell fragments in the blood that help it clot) in a microliter of blood. It is part of a standard Complete Blood Count (CBC). No fasting is required. A standard blood draw is performed.

Measures how well platelets (the blood cells responsible for clotting) clump together to stop bleeding. You may be asked to stop taking certain medications (like aspirin) for a week before the test. A standard blood draw is performed.

An overnight test that records brain waves, oxygen levels, heart rate, breathing, and eye/leg movements during sleep. Sensors are painlessly attached to the body. Avoid caffeine and alcohol on the day of the test.

Measures serum potassium (an essential electrolyte mineral that regulates nerve and muscle function, especially the heartbeat). Fasting is usually not required. A standard blood draw is performed.

Measures prealbumin (a protein made by the liver that changes quickly, making it a good marker for short-term changes in nutritional status or inflammation). No fasting is usually required. A standard blood draw is performed.

Measures progesterone (a female hormone that prepares the uterine lining for pregnancy and regulates the menstrual cycle). The timing of the blood draw depends on the menstrual cycle or pregnancy trimester. A standard blood draw is performed.

Measures prolactin (a hormone produced by the pituitary gland that stimulates milk production). It is best drawn in the morning, 3–4 hours after waking up, while fasting. Avoid breast stimulation or heavy exercise before the test. A standard blood draw is performed.

Measures PSA (a protein produced by the prostate gland, used as a marker for prostate health). Avoid ejaculation and vigorous exercise (like cycling) for 48 hours before the test, as they can temporarily raise levels. A standard blood draw is performed.

Uses TRUS (Transrectal Ultrasound, where a small probe is gently inserted into the rectum) to create detailed images of the prostate gland. An enema may be recommended beforehand to clear the bowel.

Measures Protein C (a natural anticoagulant, or blood-thinning protein, produced by the liver that helps prevent abnormal blood clots). Fasting may be required, and blood thinners can affect the result. A standard blood draw is performed.