Understanding Lab Tests for Lupus

Anybody with lupus will tell you that, at least in the beginning, you might feel like a human pincushion. There isn’t a single definitive test to diagnose lupus, so your doctor will order several blood, urine, and other tests. Because lupus can resemble many other conditions, it may sometimes take months or even years, to arrive at a diagnosis.

After you’re diagnosed, testing will continue in order to monitor the disease and track its effects on your body. That may seem like a lot of tests, but thanks to the results they provide, your doctor is more likely to identify and treat problems before they can seriously affect your health and well-being.

Here are some of the tests your doctor may order:

Routine blood tests: Your blood contains red blood cells, white blood cells, and platelets. A complete blood count measures levels of each one. Low numbers could indicate lupus.

Urinalysis: Lupus can damage the kidneys, so urine tests are crucial for detecting whether any kidney issues exist. One type of urine test checks for cell casts—parts of cells that are normally removed when your kidneys are functioning properly.

Antinuclear antibody (ANA) test: This blood test searches for ANAs, antibodies (proteins) that bind to the nucleus of a cell and can damage or destroy the cell. About 97 percent of people with lupus test positive for ANAs, but so do many people who do not have lupus.

Tissue biopsy: In a biopsy, a doctor removes a small piece of tissue and examines it under a microscope. When you have lupus, your doctor might biopsy your skin or kidneys to find out how much inflammation or damage has occurred.