What Is RA?

By Genentech
What Is RA?

Rheumatoid arthritis (RA) is a long-term disease that occurs when your immune system doesn't work the way it should. So if you have RA, instead of just protecting you from harmful events like infections, your immune system also attacks your body. This attack causes the joints and surrounding tissues to swell. This can cause achy joints among other problems.

RA and the immune system

In a healthy immune system, many different cells protect the body. Some of those cells are white blood cells, including B and T cells. All of them fight harmful germs and viruses.

Our immune system uses messengers called cytokines to tell the cells when and where to attack.

There are many different cytokines. But those most important to RA are:

  • Tumor necrosis factor (TNF)
  • Interleukin-1 (IL-1)
  • Interleukin-6 (IL-6)

Most people with RA have too many cytokines. The extra cytokines increase activity of the B and T cells.  Too much activity causes the B and T cells to attack healthy cells rather than unhealthy ones. This plays an important role in RA.

1.3 Million people have RA
It’s estimated that 1.3 million people in the United States have RA. That’s almost 1% of all adults. And women are 2 to 3 times more likely to have RA than men.

Signs and symptoms of RA

Joint pain is one of the most common symptoms of RA. It often goes along with warmth, redness, tenderness, and swelling in the joints. Here are the most common symptoms other than swollen joints:

  • Inflammation
  • Joint pain
  • Stiffness, especially in the morning
  • Difficulty performing activities

Pain symptoms will usually happen symmetrically, which means on both sides of your body.

Without proper treatment, joint damage from RA can lead to disability. Over time your joints can become permanently damaged.

That’s why it’s important to get a diagnosis as early as possible. If you think you may be experiencing RA symptoms, make an appointment to see your doctor or healthcare team.