What the Connection Between Arthritis and Low Platelets Actually Is
Some types of arthritis can lower your blood platelet count, but it is not common and depends on which kind of arthritis you have. Platelets are blood cells that help your blood clot. A low platelet count is called thrombocytopenia. Rheumatoid arthritis and lupus (which causes a type of arthritis) are the two conditions most likely to affect platelet numbers. Other forms of arthritis, like osteoarthritis, do not typically lower platelets on their own.
The connection happens in two ways. First, the disease itself can damage bone marrow or trigger your immune system to destroy platelets. Second, some of the medications used to treat arthritis — particularly certain disease-modifying drugs — can lower platelet counts as a side effect. If you have arthritis and your doctor has mentioned low platelets, the cause could be either the disease or the treatment, and that matters for what happens next.
Key Takeaways
- Rheumatoid arthritis and lupus can lower platelet counts, but osteoarthritis typically does not.
- Low platelets from arthritis happen when the disease damages bone marrow or when your immune system attacks the platelets themselves.
- Some arthritis medications, including methotrexate and certain biologics, can reduce platelet counts as a known side effect.
- A blood test showing low platelets should prompt a conversation with your doctor about whether your arthritis disease or your arthritis medication is the cause.
Which Types of Arthritis Are Most Likely to Lower Platelets
Rheumatoid arthritis is the arthritis type most commonly linked to low platelet counts. In rheumatoid arthritis, your immune system attacks the lining of your joints, and it can also attack other tissues, including blood cells. When this happens, platelet counts may drop. The drop is usually mild — most people with rheumatoid arthritis who develop low platelets still have counts in a range that does not cause bleeding problems.
Lupus (systemic lupus erythematosus, or SLE) is another autoimmune disease that often includes joint pain and is sometimes called lupus arthritis. Lupus frequently causes low platelet counts because the disease produces antibodies that attack platelets directly. People with lupus are more likely than those with rheumatoid arthritis to have noticeably low counts.
Other arthritis types — including osteoarthritis, gout, and psoriatic arthritis — do not typically lower platelet counts as part of the disease itself. If you have one of these conditions and your blood work shows low platelets, the cause is more likely to be medication, another health condition, or something unrelated to your arthritis.
How Arthritis Medications Can Lower Platelet Counts
Several drugs used to treat arthritis can reduce platelet production or survival. Methotrexate, one of the most common disease-modifying drugs for rheumatoid arthritis, can lower platelet counts in some people. Biologic medications — drugs like TNF inhibitors (infliximab, etanercept) and others — can also affect platelets, though this is less common. Older medications like gold salts and penicillamine, used less often now, carried a higher risk.
The risk is usually small, and most people taking these drugs have normal platelet counts. However, your doctor monitors this by ordering blood tests regularly — typically every 4 to 12 weeks when you start a new arthritis medication or change your dose. If your platelet count drops, your doctor may lower your dose, switch you to a different medication, or add a medication to protect your platelets.
Over-the-counter pain relievers like ibuprofen and naproxen can also affect platelets if taken regularly at high doses, though this is rare. If you take these for arthritis pain, mention it to your doctor so they know the full picture of what you are taking.
Symptoms That May Suggest Low Platelets
Many people with low platelet counts have no symptoms at all and only find out through a blood test. However, if your count drops significantly, you might notice unusual bruising, small red or purple spots on your skin (called petechiae), bleeding gums, nosebleeds that are hard to stop, or heavier-than-normal menstrual bleeding.
These symptoms do not mean your arthritis is getting worse — they mean your platelet count has dropped enough to affect clotting. If you notice any of these signs, contact your doctor. Do not wait for your next scheduled appointment. A straightforward blood test can measure your platelet count and tell your doctor whether action is needed.
It is important to know that low platelet counts caused by arthritis or arthritis medications are usually mild and do not require treatment beyond monitoring or adjusting your medication. Severe thrombocytopenia is rare in people with arthritis alone.
What Your Doctor Will Do If Your Platelets Are Low
If a blood test shows low platelets, your doctor will first determine the cause. They will ask about your symptoms, review your medications, and may order additional blood tests to check for antibodies or other signs that your immune system is attacking platelets. They will also ask whether the low count is new or has been present for a while.
If the cause is your arthritis medication, your doctor may reduce the dose, switch you to a different drug, or add a medication to support platelet production. If the cause is the arthritis disease itself, treatment that better controls your arthritis may also improve your platelet count. In rare cases where the count is very low and causing bleeding, your doctor might refer you to a hematologist (blood specialist) for additional treatment.
Continue taking your arthritis medication unless your doctor tells you to stop. Stopping suddenly can make your arthritis worse, and the benefit of controlling your arthritis often outweighs the small risk of low platelets. Your doctor will help you weigh the risks and benefits for your specific situation.
When to Contact Your Doctor About Platelets and Arthritis
Contact your doctor if you notice unusual bruising, persistent nosebleeds, bleeding gums, or small red or purple spots on your skin. Also reach out if you are scheduled for blood work and your previous test showed low platelets — your doctor needs to know whether the count is stable, improving, or getting worse.
If you are starting a new arthritis medication, ask your doctor how often you will have blood tests and what platelet count range they are watching for. This is a normal part of monitoring, and it means your doctor is checking for side effects before they become a problem. Do not skip these blood tests, even if you feel fine.
Frequently Asked Questions
Can osteoarthritis cause low platelet counts?
Osteoarthritis does not typically lower platelet counts. If you have osteoarthritis and your blood work shows low platelets, the cause is likely something else — another health condition, a medication you are taking, or an unrelated issue. Talk to your doctor about what might be causing it.
If my platelets are low, do I need to stop taking my arthritis medication?
Not necessarily. Your doctor will weigh whether the medication is helping your arthritis enough to justify the low platelet count, or whether switching to a different drug makes sense. Stopping arthritis medication suddenly can make your condition worse. Work with your doctor on a plan that addresses both your arthritis and your platelet count.
How often should I have blood tests if I take arthritis medication?
Most people starting a new arthritis medication have blood tests every 4 to 12 weeks at first, then less often once the dose is stable. Your doctor will tell you the schedule based on your specific medication and health history. These tests catch side effects early, when they are easiest to manage.
Is a low platelet count from arthritis dangerous?
Low platelet counts caused by arthritis are usually mild and do not cause bleeding problems. Severe thrombocytopenia is rare in people with arthritis. However, if your count drops significantly, your doctor will monitor you closely and may adjust your treatment to bring it back to normal.
Can lupus arthritis cause more severe low platelet counts than rheumatoid arthritis?
Yes, lupus is more likely to cause noticeably low platelet counts than rheumatoid arthritis. This is because lupus produces antibodies that directly attack platelets. If you have lupus and low platelets, your doctor will monitor your count regularly and may adjust your lupus treatment to improve it.