Ganglion cysts are the most common reason for a lump on your wrist. The good news is that they are usually harmless and don’t require treatment unless they’re bothering you.
However, there are other reasons why you may have a lump on your wrist – and some of these conditions can be serious. So, it’s important to know about other possible causes and signs that you should see a doctor.
Read on to learn more about ganglion cysts, other reasons you may have a lump on your wrist and when to get help.
A ganglion cyst is a noncancerous growth that develops near tendons and joints
Ganglion cysts are round or oval-shaped, fluid-filled lumps that form just under the skin. They are noncancerous and usually harmless. These cysts can form along any joint (the area where two bones come together) or tendon (a cord of tissue that connects muscles to bones).
Most of the time, they develop on the back (top) of the wrist, but you can also get them on your hands at the base of a finger, near fingernails and on the inside of the palm. Less often, ganglion cysts form on feet, knees and ankles.
Ganglion cysts can get larger with time or as you move the surrounding area. They’re usually between the size of a pea and the size of a quarter, but if located on a joint that you move a lot, they can be larger – sometimes growing to the size of a golf ball. Or, they can be too small to feel.
Ganglion cyst symptoms depend on the size and location of the lump
In many cases, ganglion cysts don’t cause symptoms unless they get larger. If a ganglion cyst presses on a nerve, it can cause hand pain or numbness in your hands and fingers. Large cysts on the wrist joint may also limit your hand’s range of motion, which can be uncomfortable and affect grip strength.
What causes ganglion cysts?
Doctors don’t know exactly what causes ganglion cysts. It’s possible they may form after an injury to a tendon or joint, but in many cases, there doesn’t seem to be a specific cause. However, some people are more likely to get a ganglion cyst.
Risk factors for ganglion cysts
- Sex – Anyone can get ganglion cysts, but they are more likely in women (and those assigned female at birth) between the ages of 20 and 50.
- Osteoarthritis – Ganglion cysts near fingernails are more common in people with osteoarthritis in the joint nearest the fingernail.
- Tendon or joint injury – Ganglion cysts are more likely near joints or tendons that have been injured due to trauma or overuse. For example, an athlete who performs repetitive wrist motions may develop a ganglion cyst as a sports-related wrist injury.
Treatment of ganglion cysts depends on your symptoms
Ganglion cysts don’t need to be treated unless they’re bothering you. Symptoms of cysts can often be treated at home, but a hand specialist can also provide treatments for ganglion cysts. The lumps may even go away on their own – but it can take anywhere between a few weeks and a year
Signs the lump may not be a ganglion cyst
There are other causes for a lump on a wrist. In some cases, wrist lumps caused by other conditions may have very different symptoms. However, it can sometimes be difficult to tell what’s causing the lump on your hand, so it’s always a good idea to talk to a doctor about it, even if you think it’s a ganglion cyst.
Signs that a lump may not be a ganglion cyst
Lumps caused by other conditions may have symptoms that are not usual for ganglion cysts. It’s less likely to be a ganglion cyst if the lump is:
- Located away from a joint
- Growing very quickly
- Not round or oval in shape
- Very firm to the touch
- A different color than the surrounding skin
When it’s not a ganglion cyst: Other causes for a lump on the wrist
Though ganglion cysts are the most common causes of lumps on wrists, there are other possible causes. The conditions listed below could cause lumps due to swelling, infections, abnormal cellular growth and bulging blood vessels.
Giant cell tumor of the tendon sheath (GCTTS)
It’s possible that the lump on your wrist could be a giant cell tumor growing from the tendon sheath (a layer of connective tissue that surrounds some joints). These tumors are noncancerous.
Lumps caused by GCTTS feel more firm and solid than ganglion cysts – and they can be irregular in shape. Symptoms include joint swelling and pain when you move the affected area. Some people may feel a “locking” or “catching” sensation with joint movement. Talk to your doctor if you have a growing lump that is affecting your hand function.
Epidermal inclusion cyst
An epidermal inclusion cyst is another type of round, fluid-filled lump that forms under your skin. These bumps can occur when something’s preventing skin cells from leaving the body. This can be due to a blocked hair follicle (the opening in your skin where the hair grows out) or an injury to the skin.
These cysts often have a dark dot at the center and may make your skin look redder or darker than the surrounding skin. Epidermal inclusion cysts usually don’t cause symptoms and don’t need to be treated. But if they get painful, inflamed or infected, treatment may be necessary. So talk to your doctor if you have a lump that feels warm, changes color or bursts open.
Rheumatoid nodules
About 25% of people with rheumatoid arthritis have rheumatoid nodules. These are lumps that form under the skin, usually close to joints affected by rheumatoid arthritis. The lumps can be firm or soft. Most of the time they’re round, but they can also be linear in shape. Some move around while others do not. They’re usually not painful unless they’re inflamed. If you have rheumatoid nodules that are bothering you, talk to your rheumatologist.
Gouty tophi
Some people with gout develop gouty tophi, which are swollen growths around the joints. Gout happens when the body makes too much or can’t get rid of a chemical called uric acid. The excess uric acid forms crystals that collect around the joints and surrounding tissues. Over time, these crystals can clump together to form larger masses known as tophi.
Gouty tophi are usually white in color and not painful unless inflamed. If you have gout or think you are developing a gouty tophus, talk to your doctor. There are medications that help treat gout. Sometimes surgery is helpful to prevent further damage to joints or tendons.
Carpal boss
If you have a hard lump on your wrist that feels like bone, it may be a carpal boss (or carpometacarpal boss). A carpal boss is a bony overgrowth that feels like a firm lump on the back of your wrist. It develops in the place where the bones in your pointer and middle fingers connect to your wrist bones. A carpal boss doesn’t usually cause symptoms, but some people may feel pain when they move their hand. If you have a carpal boss that doesn’t cause pain, you likely won’t need treatment, but your doctor might want to keep an eye on it.
Trigger finger
The main symptom of trigger finger is having a finger (or thumb) that catches or locks in a bent position. It can also cause a lump in the palm of your hand or a lump near your wrist. Your finger may also feel stiff or painful when you try to bend it. If your finger is locked in a bent position, your doctor or a hand therapist can recommend the best treatment to loosen it.
Foreign object or substances
A lump can form on your wrist if a foreign object (like a wooden splinter or glass fragment) gets stuck under the skin. When the skin is pierced, it also creates an entry point for microbes to enter, which can lead to an infection. A lump caused by a foreign object often goes away on its own, but if it’s red, warm or especially sore, or you think you still have a foreign body in your hand, you should see a doctor.
Wrist aneurysms
An aneurysm is an abnormal bulging of blood vessels, often due to weakness in the vessel wall. Aneurysm symptoms include an unusual pulsing sensation, and sudden and severe pain. Wrist aneurysms are rare, but if you think you have one, you should call a doctor right away.
Other noncancerous tumors
Although it’s rare, a lump on your wrist could also be caused by other noncancerous tumors. Noncancerous tumors can form throughout the body and grow out of different types of cells, including those found in fat, nerves, muscles and connective tissues. Some examples of these tumors are lipomas (fat), Schwannomas (nerve), fibromas (tendons), hemangiomas (blood vessels), vascular malformations (blood vessels), or glomus tumors (muscle around blood vessels).
Lumps caused by noncancerous tumors can be soft or firm. You may or may not need treatment – it depends on the symptoms the lump is causing and how it’s affecting your life.
Cancer of the wrists
It’s very unlikely for a lump on a wrist to be caused by cancer. But sometimes cancer forms in the hand’s connective tissues, skin, cartilage, bones, blood vessels or lymph vessels. Lumps caused by cancer are usually hard. But it’s important to remember that not all hard lumps are cancer.
When cancer forms in the wrist, it usually starts with painless swelling. With time, the lump may get bigger, and you may experience symptoms such as increasing pain, bruise-like coloring, a scaly surface, a pressure inside the lump, nonhealing wounds and swelling around the joint.
Diagnosing the cause of a lump on your wrist
If you have a lump on your wrist, your doctor will do a physical exam. During the exam, it’s likely that they’ll shine a light through the lump in a process called transillumination. If the lump glows, it means it’s filled with fluid and could be a ganglion cyst. If it doesn’t glow, it means the lump is solid and is caused by something else.
They’ll also ask you about symptoms such as pain and stiffness, and whether your symptoms are worse at different times of the day or during certain activities. Your doctor may also do imaging tests (like an X-ray, ultrasound or MRI) or take a tissue sample (biopsy) from the lump to be examined under the microscope.
When to talk to a doctor about a lump on your wrist
Some wrist lumps, like ganglion cysts, don’t need to be treated unless they’re causing problems. Often wrist lumps go away on their own or never get big enough to cause pain or other symptoms.
Still, it’s always a good idea to talk to your primary care doctor about your symptoms, and be sure to make an appointment if you have a lump that:
- Is growing quickly
- Is painful, swollen, red or warm to the touch
- Is in a location that’s easily irritated
- Comes with symptoms such as numbness, tingling or muscle weakness
Your primary care doctor can confirm what’s causing the lump and provide treatment if necessary. If appropriate, they’ll refer you to a hand specialist or other expert for advanced treatment.
