Arthritis is joint inflammation that causes pain, stiffness, and sometimes swelling

Arthritis means your joints — the places where two bones meet — become inflamed. That inflammation causes pain when you move, stiffness especially in the morning or after sitting still, and sometimes visible swelling. Arthritis is not one disease. There are over 100 types, but a few account for most cases in older adults. The two most common are osteoarthritis, which comes from wear and tear on joints over time, and rheumatoid arthritis, which is an autoimmune condition where your immune system attacks the lining of your joints.

Arthritis can develop in any joint — hands, wrists, knees, hips, feet, neck, or lower back. Some types affect only one joint or a few. Others spread across many joints at once. The pain may come and go, or it may be constant. Stiffness is often worst in the morning and improves as you move around, though it can return after long periods of rest or activity.

Key Takeaways

  • Osteoarthritis develops when the protective cartilage in joints wears down over years, and it is the most common type in seniors.
  • Rheumatoid arthritis is an autoimmune disease where the body attacks joint linings, often affecting multiple joints on both sides of the body at the same time.
  • Other types include gout (caused by uric acid crystals), lupus, and psoriatic arthritis, each with different causes and patterns.
  • Symptoms vary by type and person, but pain, stiffness, swelling, and reduced range of motion are common across most forms.
  • A doctor can identify which type you have through physical exam, blood tests, and imaging, which matters because treatment differs by type.

Osteoarthritis: wear and tear on joints over time

Osteoarthritis happens when the cartilage that cushions the ends of your bones gradually wears away. Cartilage is smooth tissue that lets bones glide past each other without friction. As it thins, bone starts rubbing on bone, causing pain and stiffness. This usually develops slowly over many years, which is why it is most common in people over 65, though it can start earlier.

Osteoarthritis often affects joints you use most: knees, hips, hands, and the lower spine. You might notice pain that gets worse as the day goes on, or stiffness that improves after you move around for a few minutes. Unlike some other types of arthritis, osteoarthritis usually does not cause redness or warmth in the joint, and it does not spread to other parts of your body.

Risk factors include age, previous joint injury, being overweight, and family history. Women are more likely to develop osteoarthritis than men, especially after age 50. The condition is not reversible, but treatment can reduce pain and help you stay active.

Rheumatoid arthritis: an autoimmune attack on joint linings

Rheumatoid arthritis (RA) is different from osteoarthritis because it is an autoimmune disease. Your immune system mistakenly attacks the synovium, the thin lining inside your joints. This causes inflammation, pain, swelling, and warmth in the affected joints. Over time, this inflammation can damage the cartilage and bone underneath.

RA often affects multiple joints at the same time, usually on both sides of your body — both hands, both knees, or both feet. It can develop at any age but most often starts between ages 40 and 60. Morning stiffness is common and may last an hour or more. You might also feel tired, have a low fever, or lose your appetite.

RA can develop quickly over weeks or months, unlike osteoarthritis which takes years. Blood tests can detect markers of RA, such as rheumatoid factor or anti-CCP antibodies. Early treatment with medications that slow the disease is important because it can prevent permanent joint damage. Without treatment, RA can cause lasting disability.

Other types: gout, lupus, and psoriatic arthritis

Gout is caused by uric acid crystals that build up in joints, usually starting in the big toe. It causes sudden, severe pain, redness, and swelling that may last days or weeks, then go away completely until the next attack. It is more common in men and can be managed by lowering uric acid levels through diet and medication.

Lupus is an autoimmune disease that can affect many parts of your body, including joints, skin, kidneys, and heart. Joint pain and swelling are often early signs. Lupus is much more common in women and people of color. It requires ongoing medical care because it can affect vital organs.

Psoriatic arthritis develops in some people who have psoriasis, a skin condition. It can cause joint pain, swelling, and stiffness, often in the hands, feet, and spine. It may start before or after the skin rash appears. Like RA, it is an autoimmune condition and benefits from early treatment.

Other less common types include ankylosing spondylitis (affecting the spine), polymyalgia rheumatica (causing muscle pain and stiffness), and infectious arthritis (caused by bacteria or viruses). Each has different patterns and requires different treatment approaches.

How doctors tell which type you have

Your doctor will start with questions about when the pain began, which joints hurt, whether it is worse at certain times of day, and whether anyone in your family has arthritis. They will examine your joints for swelling, warmth, redness, and range of motion.

Blood tests can show markers of inflammation and help identify autoimmune types. A test called erythrocyte sedimentation rate (ESR) or C-reactive protein (CRP) measures inflammation in your body. Tests for rheumatoid factor and anti-CCP antibodies point toward RA. Tests for uric acid levels can suggest gout.

Imaging — X-rays, ultrasound, or MRI — shows the structure of your joints and can reveal cartilage loss, bone damage, or fluid buildup. X-rays are often the first step because they are quick and inexpensive. MRI gives more detail but costs more and takes longer.

Identifying the type matters because treatment is different. Osteoarthritis is managed with pain relief and joint protection. RA and other autoimmune types need medications that calm the immune system. Gout needs uric acid management. Your doctor may refer you to a rheumatologist, a specialist in arthritis and autoimmune diseases, especially if the diagnosis is unclear or if you have an autoimmune type.

Symptoms that vary by type and person

Pain is the most common symptom across all types, but it feels different depending on the cause. Osteoarthritis pain is often described as a dull ache that worsens with activity and improves with rest. RA pain is often accompanied by swelling and warmth and may feel sharper or more constant.

Stiffness is common in all types but is usually worst in the morning or after sitting still. In osteoarthritis, stiffness often improves within 30 minutes of moving around. In RA, morning stiffness may last an hour or longer and is considered a key sign of the disease.

Swelling and redness are more typical of autoimmune types like RA than of osteoarthritis. Reduced range of motion — difficulty straightening or bending a joint fully — can happen with any type as the condition progresses. Some people also experience fatigue, especially with autoimmune types.

Symptoms can change day to day or week to week. Some people have flares, periods when symptoms get much worse, followed by quieter periods. Others have steady, unchanging pain. The pattern depends on the type and on how well the condition is controlled with treatment.

When to see a doctor about joint pain

See your primary care doctor if you have joint pain that lasts more than a few weeks, swelling that does not go down, morning stiffness that lasts longer than 30 minutes, or pain that limits your daily activities. These are signs that something needs evaluation and treatment.

Seek urgent care if a joint becomes suddenly red, hot, swollen, and painful, especially if you also have fever. This can signal infection or a severe flare that needs prompt attention.

Tell your doctor about any family history of arthritis, previous joint injuries, or other health conditions you have. Mention what makes the pain better or worse, what time of day it is worst, and how it affects your ability to work, exercise, or do daily tasks like dressing or cooking. This information helps your doctor narrow down which type you might have.

Frequently Asked Questions

Can arthritis go away on its own?

Osteoarthritis does not go away because the cartilage damage is permanent, though pain can be managed. Some autoimmune types like RA can go into remission with treatment, meaning symptoms improve significantly or disappear, but the disease is still present. Gout attacks come and go, but the underlying uric acid problem remains unless treated.

Is arthritis the same as arthralgia?

No. Arthralgia means joint pain without inflammation. Arthritis means the joint is actually inflamed — swollen, warm, or stiff. You can have arthralgia from many causes, including overuse or muscle strain, without having arthritis. A doctor can tell the difference through examination and blood tests.

Can you have more than one type of arthritis at the same time?

Yes. Some people develop osteoarthritis in their knees while also having RA in their hands. Others may have gout in their feet and osteoarthritis in their hips. Each type is treated separately, so your doctor needs to identify all of them to create the right treatment plan.

Does weather really affect arthritis pain?

Many people report that their arthritis pain worsens in cold, damp weather or before storms, though scientific studies show mixed results. Changes in barometric pressure may affect fluid in joints or nerve sensitivity. Whether the link is real or not, if you notice a pattern, tracking it can help you plan activities and prepare for flares.

What is the difference between arthritis and osteoporosis?

Arthritis is joint inflammation. Osteoporosis is bone loss that makes bones weaker and more likely to break. You can have both conditions at the same time, but they are separate diseases with different causes and treatments. Arthritis affects how joints work; osteoporosis affects bone strength.