Understand your lab results

Got a blood test back and not sure what the number means? Pick a test to see whether your value falls in the typical range and what a low, normal, or high result may indicate. Everything runs in your browser — nothing you type is stored. These are educational explainers, not a diagnosis.

Thyroid

TSH

TSH is made by the pituitary gland to tell the thyroid how much thyroid hormone to release.

Free T4

Free T4 is the unbound, active form of the main thyroid hormone thyroxine circulating in your blood.

Hormones & menopause

FSH

FSH is a pituitary hormone that stimulates the ovaries.

Metabolic

HbA1c

HbA1c reflects your average blood sugar over roughly the past 2–3 months, by measuring how much glucose is attached to hemoglobin.

Heart & lipids

LDL Cholesterol

LDL carries cholesterol to your tissues; high levels can build up in artery walls, which is why it's called 'bad' cholesterol.

HDL Cholesterol

HDL helps carry cholesterol away from arteries back to the liver, which is why higher levels are generally protective.

Triglycerides

Triglycerides are the most common type of fat in the blood; high levels are associated with heart disease and, when very high, with pancreatitis.

Iron & blood

Ferritin

Ferritin reflects how much iron your body has in storage.

Bone & nutrients

Vitamin D

25-hydroxyvitamin D is the main circulating form of vitamin D and the standard measure of your vitamin D status.