It often begins subtly — a joint feels puffy, unusually warm, or slightly stiff. Then it returns. Then it spreads. For many individuals, this pattern unfolds gradually and without explanation, delaying diagnosis for months or even years. But at ARBDA, we specialize in recognizing these early patterns and helping patients get ahead of the diagnosis, not behind it.
We understand how disruptive joint symptoms can be. That’s why our team of rheumatologists works with patients across New Jersey to uncover the root cause of inflammation and get them back to feeling like themselves again. Let’s break down what warm, swollen joints might mean, and when it’s time to talk to your doctor.
What Does It Mean When a Joint Feels Warm or Swollen?
When a joint becomes warm, swollen, or tender, it often means your immune system is responding to something, and not always in a helpful way. This reaction is called inflammation. Sometimes it’s a protective response to an infection or injury. But when it sticks around or affects multiple joints, it may be a sign of autoimmune disease or another chronic condition.
During inflammation, immune cells release substances like histamine and bradykinin, which cause nearby blood vessels to widen. This brings more blood, immune cells, and fluid into the tissue, making the joint appear red, feel hot, and become swollen.1
These same substances also stimulate nearby nerves, which can trigger pain and stiffness. While inflammation can be part of the body’s natural healing process, persistent or unexplained symptoms may point to an underlying condition and should be evaluated by a medical professional.
Common Causes of Hot, Swollen Joints
Many conditions can lead to joint inflammation, from autoimmune diseases to infections and even lifestyle factors. Here’s a closer look at some of the most common culprits:
- Rheumatoid Arthritis (RA): RA is a type of inflammatory arthritis where the immune system mistakenly attacks the lining of your joints. This results in warm, swollen, and often symmetrical joint pain, especially in the hands, wrists, and knees. RA can also cause fatigue, low-grade fever, and long-term joint damage if left untreated.1,2
- Psoriatic Arthritis (PsA): People with psoriasis (a skin condition) may develop PsA, which affects both skin and joints. PsA symptoms can include swollen fingers or toes that resemble sausages, joint stiffness, and pain, often worse in the morning. PsA tends to flare and remit, making diagnosis tricky without specialist care.3
- Lupus (Systemic Lupus Erythematosus, or SLE): Lupus is a chronic autoimmune disease that can impact joints, skin, kidneys, heart, and more. Joint pain in lupus may mimic RA, but lupus can also cause rashes, mouth ulcers, and sensitivity to sunlight. Flares can trigger sudden joint warmth and swelling.4
- Gout: Gout is caused by the buildup of uric acid crystals in joints, typically starting in the big toe. The pain comes on quickly, often at night, and the affected joint may look red, feel hot, and be exquisitely tender. Gout attacks can be triggered by diet, alcohol, or dehydration.5
- Osteoarthritis (OA): OA is the most common form of arthritis and occurs when the protective cartilage that cushions the ends of bones gradually breaks down. This tissue breakdown leads to joint pain, stiffness, and decreased mobility over time. While OA is not primarily driven by inflammation like autoimmune forms of arthritis, some mild swelling and warmth may still occur — particularly after extended use of the affected joint.6
- Infectious (Septic) Arthritis: Caused by bacteria, viruses, or fungi, septic arthritis is a medical emergency. It typically affects a single joint, like the knee, and comes with intense pain, fever, and redness. Immediate treatment is essential to prevent permanent joint damage.7
- Other Causes: Injury, overuse, allergic reactions, and certain medications can also contribute to joint swelling and warmth.
Inflammatory Arthritis: Rheumatoid Arthritis, Psoriatic Arthritis, and Others
Inflammatory arthritis refers to a group of autoimmune diseases where the body’s immune system goes into overdrive and targets healthy joint tissue. Unlike osteoarthritis, which is mechanical and degenerative, inflammatory arthritis involves swelling, pain, and damage that’s driven by the immune system itself.8
Rheumatoid arthritis is perhaps the best-known form, but psoriatic arthritis, ankylosing spondylitis, and undifferentiated inflammatory arthritis are also in this category. These conditions often affect multiple joints, flare unpredictably, and can also involve other organs. If caught early, treatments can calm the immune response and slow progression significantly.
How Lupus (SLE) Affects Joints
Lupus is often called “the great imitator” because it can mimic many other conditions. One of the most common symptoms of lupus is joint pain and swelling, typically in the hands, wrists, and knees.4 Unlike rheumatoid arthritis, lupus-related joint pain tends to be less destructive to the joint itself, although it can still be quite painful.9
The joint symptoms in lupus often coincide with flares, which is when the disease becomes more active. During a flare, joints may feel especially tender, warm, and stiff. Because lupus is systemic, other symptoms like rashes, fatigue, and organ involvement may also be present.
Diagnosing lupus requires a combination of blood tests, symptom tracking, and imaging studies, typically coordinated by a rheumatologist.
How Gout Affects Joints
Gout is a painful and sometimes misunderstood type of arthritis caused by uric acid buildup in the bloodstream. When levels get too high, uric acid can form sharp crystals that deposit in joints. This most often occurs in the big toe, though other joints like the ankle, knee, or fingers can also be affected.5
A gout attack usually strikes suddenly. One minute everything’s fine, and the next, the joint is swollen, red, hot, and extremely tender — so much so that even the weight of a bedsheet can feel unbearable. Left untreated, gout can become chronic and damage joints permanently.10
The good news is that medications and lifestyle changes can help manage and prevent future attacks. For the 12-35% with gout who develop tophi, surgery is also an option.10
How Weather, Heat & Hydration Affect Joint Warmth
Many people report their joint symptoms worsen with changes in temperature or humidity. Studies show a correlation between higher humidity and increased swelling and pain.11 On the flip side, dehydration can reduce joint lubrication, leading to discomfort and stiffness.12
Staying well-hydrated and maintaining a healthy electrolyte balance can help ease these effects. For those living with chronic joint issues, tracking how symptoms change with the weather may provide helpful insights for managing flares.
Diagnosing the Cause: What to Expect
When you visit your primary care doctor for joint swelling and warmth, they’ll ask detailed questions about your symptoms, lifestyle, and medical history. Physical exams will assess which joints are affected and how severe the inflammation is. Depending on the suspected cause, your doctor may order blood tests, X-rays, ultrasounds, or even joint fluid analysis to check for infection or crystals.
This diagnostic process helps rule out potential causes and confirm the correct condition so the right treatment can begin. Early diagnosis is key, especially for autoimmune conditions that can worsen over time if left untreated.
New Jersey’s Best Rheumatologists Are Ready to Help You!
At ARBDA, our board-certified rheumatologists are passionate about getting to the root of your joint concerns. If your primary care doctor suspects your joint issues might be linked to an autoimmune or inflammatory condition, they may refer you to a rheumatologist — and that’s where we come in.
We’re proud to be one of the most experienced rheumatology practices in New Jersey, with specialists who are ready to listen, evaluate, and create a personalized treatment plan tailored just for you. We offer compassionate care, state-of-the-art testing, and access to the most up-to-date therapies in the field.
Call us or request an appointment online today at one of our convenient locations across New Jersey. Relief starts with the right diagnosis, and you deserve nothing less.
1https://www.ncbi.nlm.nih.gov/books/NBK279298/
2https://www.niams.nih.gov/health-topics/rheumatoid-arthritis
3https://pmc.ncbi.nlm.nih.gov/articles/PMC6702660/
4https://www.niams.nih.gov/health-topics/lupus
5https://www.niams.nih.gov/health-topics/gout
6https://www.niams.nih.gov/health-topics/osteoarthritis
7https://www.ncbi.nlm.nih.gov/books/NBK538176/
8https://www.ncbi.nlm.nih.gov/books/NBK507704/
9https://pmc.ncbi.nlm.nih.gov/articles/PMC9127025/
10https://www.sciencedirect.com/science/article/abs/pii/S004901721600041X
11https://www.health.harvard.edu/blog/can-the-weather-really-worsen-arthritis-pain-201511208661
