Pain on the inside of your knee can have many causes, however the most common cause is MCL injury - the injury of the ligament on the inside of the knee.
If you had a knee injury, the probable causes are medial meniscus injury and direct injury to your bone.
If you do not remember an injury, you probably have mcl tendonitis, arthritis, pes anserine bursitis, or medial plica irritation.
The most common cause for the medial collateral ligament injury is a direct blow to the outer side of the knee. This overextends the inner side, which can result in the ligament tearing. This injury is very common in contact sports including football and rugby.
Other common causes for this injury are falls and twisting of the knee.
The strained knee ligament's recovery time is between 1 to 8 weeks depending on the severity. To ensure fast recovery ice and rest the knee, take some (but not too much) pain relievers, and rest your knee. Using a brace with lateral stabilization is recommended, as side to side movements could hurt the ligament again.
You can find more information on the recovery at the UCSF Medical Center.
Sometimes this injury is combined with the next one, the medial meniscus injury as the this ligament attaches to the meniscus too.
The menisci are two letter C shaped cartilages which sit between the shin bone and the thigh bone. The menisci's job is to distribute the forces. The menisci can get damaged by contact sports or twisting, however age-related degeneration can happen easily too.
If your meniscus is torn you will feel painful cracking as the torn part gets caught up in the knee join. Feeling that your knee is locked is a common symptom too.
Meniscus tears are usually fixed by a small operation, the doctor simply removes the torn part through a small incision.
MCL tendinitis is the inflammation of the MCL. It is caused by repeated overuse of your MCL tendons. It causes strong knee pain, may cause limitation of movement and tenderness at the MCL.
The MCL tendinitis is diagnosed using X-ray and CT or MRI.
Icing the painful part, resting it and taking anti-inflammatory medication helps the tendon to heal by itself.
If the tendinitis has been developing for a long time, the MCL may calcify. Once calcified, the only real solution is the excision of the calcified part.
Tendinitis of the MCL is rare, so even if you have a gradually developing pain at your MCL, you probably have some other knee issue.
Arthritis, both osteoarthritis and rheumatoid arthritis can cause pain on the inside of the knee.
While osteoarthritis is caused by age-related degradation of the lining of the joints, rheumatoid arthritis is caused by the immune system attacking the same lining.
Rheumatoid arthritis causes the joint to swell, feel tender and warm to the touch. Osteoarthritis has the same symptoms, except for the warmness.
Osteoarthritis is usually treated with anti-pain medication. Light exercises can improve osteoarthritis.
While light exercises are beneficial in rheumatoid arthritis too, it's treatment is more intensive. NSAIDs and steroids are used to reduce the inflammation, and immunosuppressants and DMARDs are used to alter the immune system, so it does not attack your own body.
Arthritis is not curable, however the symptoms can be reduced.
The bursa are small fluid filled sacs which usually sit between a bone and soft tissue. The bursa helps reducing the friction as the tissue slides on the bone.
The most common symptom for pes anserine bursitis is pain on the inside of the knee during climbing or descending stairs. In general any movement which puts load on the hamstrings can be painful.
The bursitis often happens together with tendinitis at the same location, as both the bursa and the tendons get overloaded the same way.
Pes anserine bursitis is caused by overloading the inner knee area: sports which require lot of direction-changes, muscle imbalances, wearing the wrong shoes (!), exercising incorrectly, for example skipping the warm-ups and the stretches, and finally using your legs abnormally.
Pes anserine bursitis is usually diagnosed with the help of X-ray, MRI or ultrasound.
Pes anserine bursitis responds well to treatment: resting the leg, icing the painful area and taking anti inflammatory medication. Healing time is a few weeks.
Medial plica irritation, also known as plica syndrome, can cause pain on the inside of the knee.
If you have plica syndrome, the synovial plicae, which is a leftover from fetal development, gets inflamed from an injury or overuse.
While there are four synovial plicae folds in the knee, the one on the inside is most prone to inflammation.
If you have medial plica irritation you may hear cracking and clicking sounds besides feeling the pain, and you may feel that it's hard to extend your knee if you have been sitting for long.
Fortunately medial plica irritation is very rarely serious, and simple physiotherapy will make you feel better fast. Simple walking, biking and half squats help by strengthening your front thigh muscles, and hamstring stretches help by relaxing your hamstrings. Healing time is usually four to six weeks.
Houston Methodist has a really detailed article on Plica Syndrome.
Just like your skin, your bone can get bruised too. Getting bone bruises is easy - a strong hit to the bone from contact sports without protective gear, a physically demanding job or osteoarthritis (bone on bone contact) is all you need to get a bone bruise.
A bone bruise will also result in blue, black or purple color as the blood vessels got injured, just like a normal bruise.
If you bruised your bone near a joint, your joint will feel stiff and tender, and it will take longer to heal than a simpler bruise would.
A bruise of the inner side of the knee usually heals by itself - all you need to do is rest it, take some pain medication if you need it, and maybe ice it. The healing time is between a few weeks and a few months depending on the severity of the bruise.
If the pain or the swelling keeps increasing get to the doctor ASAP as you may have some other condition, not a bone bruise.
To lessen the chance of a bone bruise always wear protective gear. A balanced diet and strength training will make your bones stronger. Avoiding alcohol and smoking helps too.
You can read more on bone bruises at Saint Luke's Health System.
As MCL sprain is the most common injury that causes knee pain on the inner side, it's a great to know that often you can fix it with simple exercises.
These exercises strengthen the medial ligament, so it will be able to resist further injury too.
If you find the exercises painful or too hard slow down, it's not a race.
Lie on your back for this exercise on a comfortable but not too soft surface. Slowly slide your heel up towards your buttocks while keeping it on the ground. Hold it for a half minute, then slowly slide back. Repeat 10 times every other day. If you feel that the range of motion of your knee is too small, hold your leg in the upper position for longer. Do not force it.
This is a really easy exercise, you can start it as soon as you do not feel much inner knee pain. For this exercise lie on your back on a comfortable surface. Next simply contract your front thigh muscles. Hold for 10 seconds, then rest for 3 seconds. Repeat 15 times.
Lie on your back on a firm but comfortable surface, and place a small rolled-up towel under your injured knee for this exercise. Contract your front thigh muscles by pressing on the towel with the back of your knee. Hold for 5 seconds, then rest for 10 seconds, repeat 10 times. Your foot may rise from the ground as you are doing this - this is normal.
For this exercise lie on your back on a firm, comfortable surface. Lift one leg up until it's vertical. Hold the position a bit to stretch your hamstrings. Afterwards gently lower your leg back onto the ground.
For step ups stand next to stairs sideways. Step on the lowest step with your injured leg, raise your body, then lower your body again. Do 10 reps of this exercise with each leg. If you feel pain during this exercise, stop it or lower your rep count. If this exercise is too easy, get some weights in both hands.
Wall squats are advanced exercises, only try them if the previous too are already going really well.
Stand with your back against a wall, and place a soccer ball or basketball between the middle of your back and the wall. Place your feet shoulder-width apart. Next slowly squat down until your thighs are at 45 degrees. Hold it a bit, then push yourself back up. Take care that your feet are always in front of your knees. (That is your shin bone is bending towards the wall or is straight.)
This exercise will need time, keep doing it day after day and work yourself up to 3 sets with 15 repetitions.
You can also use a slippery surface with a towel too instead of a ball.
For calf raises stand with your feet shoulder-width apart. Slowly lift your heels from the floor as high as you can, hold it for a few seconds, then slowly let your heels down. Do 3 sets of 15 repetitions of this exercise. If you find this exercise too easy, do it with alternating legs.
For leg curls you will need a mid-strength resistance band. Lie on your front, with the resistance band between your ankle and an object that won't move. The resistance band should be fixed to the object near the ground.
Bend your leg at your knee, and slowly raise your foot, working against the resistance band. Keep your hips on the ground. Go for 3 sets of 15 reps when starting out. If grew stronger you can go for high-strength resistance bands, and lower the repetitions to 8.
For half squats stand with your feet just a bit wider than your shoulders. Keep your back straight, your feet pointing outwards and go down to a half-squat, until your thighs are at 45 degrees. Hold it a bit then raise yourself back up. Do 3 sets of 15 reps of this exercise. If you find it too easy grab some weights in your hands, or go down until your thighs are horizontal, or you could even do single leg squats.
For a split squat or lunge stand with your legs as if you'd do take a large step. Slowly let your body down, with your knee almost touching the ground. You can use hand-weights if you find that this exercise is too easy. Work yourself up to 3 sets of 15 repetitions.
Lie on your back, with your knees bent and your feet near your buttocks. Slowly push your hips up using your hamstrings and the muscles in your buttocks. Hold the position for a few seconds, then let yourself down. Work your way up to 3 sets of 15 reps. If you found this too easy, go for single-leg bridges - use alternating legs to push yourself up, and focus on keeping the balance.
Do yo have pain just bellow your kneecap? Check our patellar tendon pain article!