What Can Bring on Sudden Ankle Pain When You Didn’t Injure It?

Why does my ankle suddenly hurt for no reason?

If you know you haven’t been injured, and you don’t have pre-existing health conditions that you’re aware of, the pain may feel random. But there may be an underlying cause that you don’t know about — or that you didn’t connect with your ankle pain.

Osteoarthritis

With osteoarthritis, the cartilage cushion between two bones gradually wears away, causing the bones to rub up against each other. And it’s painful. You may also have some stiffness and tenderness. You might realize that it’s worse when you wake up in the morning. This condition sometimes causes pain that comes on suddenly.

Rheumatoid arthritis

When you have this chronic autoimmune disease, your body’s immune system begins attacking healthy tissue, including the lining of joints like your ankle joints.

As many as 90% of people with rheumatoid arthritis develop symptoms in their feet or ankles. The symptoms, which include pain but may also include swelling and stiffness, usually start in the toes and move toward the ankles.

Reactive arthritis

A bacterial infection in another part of your body, like your genitals or bowels, can trigger arthritis symptoms in other parts of your body. And your ankles are one of the most common areas affected by reactive arthritis, which is also known as spondyloarthropathy. Your knees, heels, and toes may also develop severe swelling and pain.

Lupus

Lupus is another autoimmune disease that causes inflammation. It tends to cause swelling, muscle pain, and joint pain in various parts of the body, including the feet and ankles.

In fact, a 2023 study stated that up to 77% of people with systemic lupus erythematosus (SLE) — the most common type of lupus — experience foot problems, with arthritis in the feet being a common symptom.

Gout

Gout is a type of inflammatory arthritis that’s very painful. It occurs because uric acid crystals build up in the joints. It most commonly affects the big toe, but it can and often does affect other joints, including the ankle. A gout flare-up can come on suddenly.

Bursitis

When the small fluid-filled sacs (bursae) that act as cushions between the bones that make up your ankle joint become inflamed, you have developed bursitis of the ankle. It can develop as a result of injury, but overuse and stress on the ankle are also possible causes.

Arthritis and gout may be responsible in some cases. Even a poorly fitting pair of shoes might cause those sacs to get inflamed and cause pain. This is a condition that can develop slowly in some cases, and you might first begin to notice swelling or pain when you stand a certain way, such as on your toes or leaning back on your heels.

Scleroderma

Also known as progressive systemic sclerosis, scleroderma is a rare autoimmune disease. Although it’s not well understood, it seems to occur when your immune system provokes the overproduction of a fibrous protein called collagen that results in thickened, hardened skin.

Inflammation caused by scleroderma can also result in swelling and damage to various organ systems, tissues, and joints. You may develop some ankle stiffness and pain, as well as pain and stiffness in other joints.

Fallen arches

When the tendons supporting the arches of your feet get damaged, the arches lose support, resulting in a condition known as fallen arches, medically known as acquired pes planus. If you have fallen arches, the entire sole of your foot touches the ground instead of leaving a little bit of daylight under the middle part of your foot.

This condition can be caused by:

• degenerative changes
• obesity
• physical trauma
• posterior tibial tendon dysfunction

Achilles tendonitis

Your Achilles tendon connects your heel to your calf muscle. An injury can rupture or tear it, but consider other reasons that you might wind up with a sore ankle. If you do a lot of walking or repetitive movements, the wear and tear can result in Achilles tendonitis.

Aging makes the tendon get weaker, too. As a result, the back of your heel may feel swollen or painful. You may have trouble moving or flexing your foot.

Osteochondral lesion of the talus (OLT)

This occurs when a previous injury accumulates damage to the cartilage and bone on top of the lower bone of your ankle joint. It may worsen during jumping or running, and you might even hear a clicking or popping sound from any loose cartilage.

Infections

An infection can work its way into your ankle and cause pain. This could be the result of bacteria, such as:

• Staphylococcus aureus
• Streptococcus
• Enterobacter

All three are known to cause bone and joint infections.

Diagnosing the cause

A medical professional will likely perform a physical examination of your ankle and foot to check your range of motion, as well as to look for swelling and possible signs of infection.

In some cases, other diagnostic tests may be necessary to rule out fractures or structural injuries. For example, an ultrasound might show damage to a tendon. Joint or bone damage might be detected via a CT scan. Bone spurs and cartilage loss can also be seen on X-ray.

If you already have a diagnosis like rheumatoid arthritis or lupus, especially if you have a history of previous episodes of ankle pain or pain in other joints, it can help your doctor get a handle on the cause.

Treatment for sudden ankle pain without an injury

The cause of the pain will direct the treatment.

Osteoarthritis

Depending on how severe your ankle pain is, your doctor may suggest nonsteroidal anti-inflammatory drugs (NSAIDs) or applying a topical cream to your ankle. Wearing a brace or shoe inserts might also help.

In much more severe cases, joint fusion surgery or ankle replacement surgery might become options.

Rheumatoid arthritis

Your doctor may recommend a combination of exercise and medication to address this cause.

An over-the-counter pain reliever may help dull the pain, but a steroid injection in the joint may help more.

You may also need a medication like a disease-modifying antirheumatic drug (DMARD) to decrease inflammation and slow the progression of the disease.

Sometimes when the back of the foot and the ankle are affected, it can make your arches fall. In this case a doctor might suggest you wear orthopedic shoes to give you some support.

Reactive arthritis

For new or early stage pain, you can take NSAIDs. If it sticks around and becomes chronic, though, your doctor may prescribe DMARDs.

Severe joint pain may necessitate biologic drugs or even corticosteroid injections into the joint. Treatment focuses on treating the underlying cause.

Lupus

Your doctor might suggest rest and NSAIDs, as well as corticosteroids or immunosuppressants. Your treatment might also depend on whether your disease is active.

Gout

If you have gout, you may be taking a medication, such as xanthine oxidase inhibitors or probenecid, to prevent painful flare-ups. But if you have a flare, your doctor may suggest an NSAID, a corticosteroid, or colchicine, which is an anti-gout medication that should alleviate the pain. It may also help prevent it.

Diet and exercise can also help you manage gout.

Bursitis

You’ll likely be sent home with a prescription for rest and anti-inflammatory meds. Applying compression or wearing a splint or brace can also help with the pain. If your doctor decides to drain any fluid from your bursae and finds an infection is causing the inflammation, you may be prescribed antibiotics.

Scleroderma

There’s not a cure for scleroderma, and there’s not one single effective treatment regimen, either.

Your doctor may aim to try to slow the progression of the disease, which may entail the use of immunosuppressants. They may also recommend NSAIDs and corticosteroids for pain, and possibly other treatments depending on how widespread the disease becomes in your body.

Fallen arches

Orthotic shoes or inserts are the most common treatment. The pain can be addressed with an OTC pain reliever, too. Certain exercises, known as short foot exercises, have been shown to ease symptoms. In rare cases, surgery may be necessary to address the fallen arches.

Achilles tendonitis

Rest and stretching exercises are usually part of the treatment, as well as wearing shoe inserts or a brace (or both). Your doctor may suggest you cut down on your physical activity for a while. Anti-inflammatory meds or corticosteroids may also help with the pain. In severe cases, tendon repair surgery may become an option.

Osteochondral lesion of the talus (OLT)

Research suggests that cartilage repair or replacement may help with OLT, but it should be undertaken thoughtfully and with regard to your specific condition.

Infections

A blood test or tissue culture (where a small sample is cut or scraped off and sent to a lab for analysis) should be able to reveal the type of bacteria causing the infection in your ankle. Then, your doctor can start you on oral or IV antibiotics to knock out the infection and alleviate pain in your ankle.

When to see a doctor

If you don’t know what’s causing your ankle pain, it’s a good idea to see a doctor. It might be a strain that will go away on its own. But it could be a sign of a progressive disease that, if left untreated, could get worse over time and cause permanent damage.