Hello there, 

Is the cold weather making your RA act up?

If your joints start yelling at you the moment the temperature drops, you’re not imagining it. Weather changes can worsen pain and inflammation in people living with rheumatoid arthritis (RA). But here’s something most people don’t know: A growing body of research shows that your symptoms are influenced not just by weather—but by invisible processes happening inside your joints, including a process called angiogenesis.

What does Angiogenesis Have to do with RA?

Angiogenesis means the formation of new blood vessels. Normally, angiogenesis is a good thing. It helps heal wounds and grow new tissue. But in RA, angiogenesis goes into overdrive.

Inside RA-affected joints, the immune system mistakenly attacks healthy tissue. Inflammation makes the lining of the joint (the synovium) expand and grow rapidly, creating a tissue mass that behaves almost like a tumor. To keep growing, that tissue needs oxygen and nutrients—so the body starts building new blood vessels at a feverish pace.

Those new vessels act like highways, allowing more and more immune cells to pour into the joint.

➡️ More blood vessels → more inflammation → more pain.

How our Environment Fuels RA

Researchers now understand that rheumatoid arthritis isn’t driven only by genetics or by the immune system “going rogue.” Instead, RA develops through an interconnected sequence of events inside the body.

Here’s the simplified model:

1. Environmental exposures create oxidative stress.
   Things like smoking, air pollution, poor diet, or chronic stress introduce free radicals — unstable molecules that damage cells.

2. Oxidative stress triggers inflammation.
   When free radicals accumulate, the immune system senses danger and responds with inflammation, releasing molecules such as TNF-α and IL-6.

3. Inflammation reduces oxygen in the joint (hypoxia).
   The inflamed joint lining begins to thicken and grow rapidly. This expanding tissue uses oxygen faster than the blood supply can deliver it, leaving the joint in a continuously low-oxygen state.

4. Hypoxia activates angiogenesis (new blood vessel formation).
   Low oxygen turns on a molecular “emergency program” inside joint cells, stabilizing a sensor called HIF-1α. HIF-1α then increases production of VEGF, the body’s command signal for building new blood vessels.

5. Angiogenesis fuels more inflammation.
   The new blood vessels act like highways, bringing even more immune cells into the joint — which restarts the cycle and makes the inflammation chronic.

This is why two people with similar genes can have completely different RA outcomes, and why RA isn’t just about joints.
It’s about biology + environment + lifestyle—and angiogenesis is the hidden mechanism connecting them.

Want to do something about your RA pain today?

Download our guide on Environmental Triggers of RA + Action Plan to learn more about what you can do to help manage your RA symptoms.

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Best wishes,
- The Angiogenesis Foundation

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