Arthritis Leg Pain & Fibromyalgia Leg Pain: What’s The Difference?

Arthritis leg pain and fibromyalgia leg pain? What’s the difference?

It’s common to get arthritis and fibromyalgia mixed up, but there are distinct differences between the two that all patients should know.

Without a doubt, we know that leg pain is utter misery.

If you’re here because you’re experiencing severe leg pain due to autoimmune arthritis or fibromyalgia, I sympathize with you. My legs are so painful all the time. They never stop hurting.

I started experiencing extreme leg pain long before my arthritis and fibromyalgia diagnoses came along. I had bouts of muscle weakness that felt like my legs were going to give out on me. Mysterious bouts of joint swelling occurred at random. Some days my legs would puff up and become hot and red. Other days they ached non stop like I’d been running or dancing for hours on end. I am amazed at how much I normalized my extreme leg pain.

Did I overdo it at the gym? Maybe my backpack was too heavy? It’s just leg cramps!

The excuses I was able to come up with still shock me. I never suspected I had a disabling chronic illness though.

Here are some things I’ve learned on this 16 year journey with inflammatory arthritis leg pain and fibromyalgia leg pain.

I suffer from autoimmune arthritis leg pain and fibromyalgia leg pain non stop. It never gives me a break.

Leg pain was the first symptom with my diseases that let me know something was really wrong. Reading back through my journals, it is mentioned consistently and I marvel at how much I’ve endured. For the longest time, I attributed my leg pain to running and working out too hard and wearing heels.

When I stopped wearing heels and the pain persisted, I knew something was not right. Walking and standing became painful all the time and that’s when I knew something was really wrong.

If you’ve read My AS Story, you know that bilateral leg swelling was my first clue.

It hit out of the blue. There was no warning. I literally went to bed one night and the next morning, I couldn’t walk or stand.

Within a week, I had my answer: Ankylosing Spondylitis, now known as Axial Spondyloarthritis. (This doesn’t happen with fibro, by the way!) I learned about fibro leg pain in 2013.

For many years I couldn’t figure out the differences between inflammatory arthritis leg pain and fibromyalgia leg pain. Now I can tell right away! Although every once in a while, fibro throws a curveball at me.

In 2024, my doctor and I thought my never-ending mid-thigh pain was avascular necrosis. The pain extended from my lower back and wrapped around my buttock . X-rays and MRIs revealed there was no visible damage in this area. That’s how we confirmed it was fibromyalgia.

Leg pain, no matter what it’s caused by is painful and debilitating. This article attempts to cover leg pain in general. I hope it helps you!

Autoimmune Arthritis Leg Pain vs Fibromyalgia Leg Pain – Venn Diagram by MySeveralWorlds.com by Carrie Kellenberger

Autoimmune Arthritis Leg Pain – Symptoms

Does this sound like you?

1. Standing on crushed glass
2. Hot, burning joints
3. Matchstick legs – like they will snap at the joints
4. Popping, grinding, crackling legs
5. Stiff as a board
6. Can’t bend your joints
7. Exquisite fire in my bones
8. Severe joint pain
9. Pain in weight-bearing joints
10. Swollen joints
11. Decreased mobility and restricted movements

Autoimmune leg pain can vary widely depending on the specific autoimmune condition causing it.

Inflammatory arthritis leg pain often results in severe stiffness. You’ll also see key signs of active inflammation in arthritis, whereas it’s not visible with fibromyalgia. If you see hot, red, swollen joints in addition to leg pain and stiffness, that’s one sign you are experiencing arthritis leg pain.

Your doctor can also run tests to verify if you have active inflammation by looking at ESR and CRP levels in your blood.

I’ve listed the most common symptoms that are specific to inflammatory arthritis leg pain in blue.

Joint Pain and Stiffness

Autoimmune conditions like rheumatoid arthritis can cause joint pain, swelling, and stiffness in the legs. The pain might be worse in the morning or after periods of rest and can improve with movement.

This pain is specific to inflammatory arthritis. It’s a common system for arthritis sufferers, particularly in the morning or after periods of inactivity. The joints in the leg may feel stiff, making it difficult to move or bend.

Swelling / Inflammation

Your joints may be swollen and tender to the touch, adding to the discomfort. This can be accompanied by warmth and redness over the affected area.

Grinding or Grating Sensation

Do your knees and joints pop and grind? Mine do! It’s very specific to arthritis and it feels like grinding or grating in the joint. This happens a lot in osteoarthritis where the cartilage has worn down.

Common Autoimmune Conditions That Cause Leg Pain

Autoimmune conditions that may lead to leg pain include:

• Spondyloarthritis (including axial spondyloarthritis, nr-axSpA, Psoriatic Arthritis and more): Joint pain, swelling, and stiffness. Pain in the lower back, buttocks, and legs.
• Rheumatoid Arthritis: Joint pain and swelling.
• Lupus: Joint and muscle pain.
• Multiple Sclerosis: Neuropathic pain, muscle spasticity.
• Vasculitis: Inflammation of blood vessels, causing pain due to reduced blood flow.
• Peripheral Neuropathy: Nerve pain that may occur with lupus, Sjögren’s syndrome, or other conditions.

Inflammatory arthritis leg pain and fibromyalgia leg pain: What’s the difference? by Carrie Kellenberger

Fibromyalgia Leg Pain – Symptoms

Does this sound like you?

1. Molasses Legs
2. Legs filled with wet cement
3. Muscle cramps and spasms in my calves. You can see my muscles twitching under the skin
4. My legs feel like jelly all the time
5. Terrible burning pain in leg muscles after activity
6. Lead legs
7. My feet are glued to the floor
8. Legs feel like they have heavy weights on them
9. Feels likeI I’ve run a marathon even though I haven’t done anything
10. I feel like I got hit by a truck
11. It feels like someone took a hammer to my legs and feet

Fibromyalgia leg pain seems to affect areas where muscles attach to the bones although this is not a rule! I’ve had deep, crippling pain happen in the center of my thighs and calves where it’s all muscle. While your fibromyalgia leg pain might feel like arthritis, it’s not as fibro doesn’t damage joints or muscles.

Nevertheless, patients find it hard to differentiate between the two because the symptom list looks the exact same.

Widespread pain is common with fibromyalgia, but joint pain isn’t.

No two fibromyalgia patients are the same so the cause of weakness and leg pain might differ. Some speculate that mitochondrial changes with circulation and metabolism are what cause pain, fatigue and weakness. ^{2020 Source}

It’s important to note that fibromyalgia is a complex condition. Symptoms can vary widely among individuals. And yet all fibro patients will recognize the following symptoms highlighted in purple.

Radiating Leg Pain

This type of pain is specific to fibromyalgia. It starts in one place and ends up in other places in your legs or in your body. Pain may sometimes radiate from the affected joint to other parts of the leg.

Widespread Sensitivity

Fibro patients have widespread sensitivity. When I say widespread, I mean all parts of your body are affected from your skin and muscles to your eyes, ears, stomach, and more.

In fibromyalgia, light touch or pressure can feel painful due to heightened sensitivity. This is known as allodynia, where non-painful stimuli are perceived as painful. This is markedly different to auto-inflammatory arthritis pain! If my body is hurting everywhere, that’s a clear indicator fibro is at work.

These sensations can fluctuate in intensity and may be triggered or worsened by factors like stress, lack of sleep, weather changes, or physical activity.

Drilling Leg Pain

This type of pain is very persistent with fibromyalgia. It’s a non-stop, deep, drilling ache that may feel like a muscle strain or soreness. It can affect one or both legs and might be more pronounced in specific areas, such as the thighs, calves, or shins.

Below are symptoms that are common to arthritis leg pain and fibromyalgia leg pain.

This list, more than anything, tells us why it’s so confusing to differentiate between the two.

Sharp or Stabbing Leg Pain

This type of pain might occur suddenly and can be quite severe. It feels intense and localized, often described as stabbing, shooting, or piercing. In some cases, the pain may feel like this during movement or weight-bearing activities.

Occasionally, fibromyalgia pain in the legs may feel sharp or stabbing, especially when moving or applying pressure to the area. I get this one a lot, especially in my mid-thighs. It literally feels like someone has driven nails through my thighs. This pain is very specific to fibromyalgia.

Cramping or Spasms

Some people experience muscle cramps or spasms, which can be quite painful. This is often due to inflammation affecting the muscles or nerves.

Muscle cramps or spasms are common. These can occur suddenly and vary in intensity, sometimes waking individuals from sleep.

Fatigue and Heaviness

Do your legs feel dead? Numbness or a feeling of “deadness” in the legs can occur when nerve damage or inflammation affects sensory perception. This sensation can be accompanied by weakness or difficulty moving the legs.

Your legs might feel heavy, tired, or fatigued, as if they have been overworked or are carrying an extra weight.

Burning and Electric Shock Sensation

A burning sensation, often described as “pins and needles” or a feeling of heat in the legs, is common in conditions like peripheral neuropathy, which can occur in autoimmune diseases such as lupus or rheumatoid arthritis.

Some people describe a burning or tingling sensation, similar to the feeling of “pins and needles” or a burning pain that radiates through the muscles.

I’ve written extensively about electric shock pain here. It literally feels like being electrocuted, but you also might experience numbness or tingling that is accompanied with a burning sensation. This causes your legs to feel really weak.

Aching or Throbbing

This type of pain is a deep, dull ache that can be continuous or intermittent. It can be exacerbated by certain activities or prolonged periods of inactivity.

While fibro pain can make you feel stiff, it’s specifically joint pain here that makes this type of pain different to fibromyalgia leg pain.

Muscle Pain, Fatigue and Weakness

Some autoimmune diseases, such as polymyositis or dermatomyositis, primarily affect the muscles, causing pain, tenderness, and weakness, especially in the thighs and upper legs. Pain and inflammation can lead to muscle weakness and a feeling of tiredness in the legs. Many autoimmune-related pains are exacerbated by physical or emotional stress, fatigue, or overuse of the affected muscles or joints.

The specific sensations can depend on the type of arthritis (such as osteoarthritis, rheumatoid arthritis, or psoriatic arthritis), the severity of the condition, and the individual’s pain threshold.

Fluctuating Pain Levels

The intensity and type of pain can fluctuate, sometimes feeling more intense during flare-ups and easing during periods of remission.

Ways to Cope With Leg Pain

Pacing

Pacing is my number one tool for coping with leg pain. Without it, my days would spin out of control. I rely heavily on my FitBit to keep a cap on the steps I take each day. I know my energy envelope poops out around 3,000 steps.

Ideally, I try to stay within that range for two reasons. The first reason is to maintain the step count I’ve held on to since 2018. The second reason is staying within this range reduces flare-ups. Going over it results in more leg pain. That’s why tracking your symptoms and recording what your triggers are is so important. Read more about pacing here.

Rest

This one seems obvious, but time and again, I meet patients who don’t understand that quality rest is needed. That means building recovery days into your schedule and staying in bed, on your couch, or your my recliner. It’s best to keep your legs up too!

I have activity centers that are located in each area of my home so I can work on something while resting. I keep a lot of art supplies within reach.

My rule of thumb is that my leg pain typically kicks in at the 48 to 72-hour mark after activity. That’s my golden triangle for rest and recovery.

Exercise

Fibro bodies hate exercise. Arthritis bodies love it. Most of us walk a fine line with exercise. My knees pop and grind all the time and they’re loose in their joints. Walking, as I’ve mentioned, is limited for me. But that’s no excuse to skip it.

Extremely gentle movement like tai chi has helped me stay active. Unfortunately, I have so much swelling all the time from arthritis, I can’t do weight bearing exercise. I never lose hope though!

Mobility Aids

Mobility aids are my best tool for movement. With canes and wheelchairs, I reduce my chances of falling. I have the support I need. I also stress less about being on my feet. Ironically, using my power wheelchair has resulted in me being able to do more. Not having to stress about walking through an outing so I can enjoy what I’m doing is huge.

I swap out mobility aids depending on how I’m feeling. If it’s a short outing, I’ll use my cane. If I’m picking up groceries, I use my wheelchair.

My wheelchair comes on all outings and I try to walk when I can. One other benefit to my power wheelchair is that it’s always more comfortable than the seats where we’re going.

Final Thoughts on Leg Pain

Learning how to live with extreme leg pain is a brutal life lesson that can often feel like you have no control over. In time, however, you might find yourself being able to work around it.

Having good coping techniques in place for days when there’s nothing to do but rest with your legs up is key to living with it. There are loads of things you can do from the comfort of bed or from your couch.

As always, reach out if you have questions or comments. I’d love to hear from you!