Causes of Throbbing Pain in the Knee & Why Does The Knee Pain Worsen During The Night?

Knee pain or any pain in the body can be a cause of great discomfort, especially if it strikes at night. Many people struggle with throbbing knee pain in the night that causes pain-induced insomnia. Knee pain in the night can be extremely frustrating and also prevent you from getting a good night’s rest, leaving you feeling fatigued. The bigger frustration, though, is not knowing the cause of this throbbing knee pain. Read on to find out everything you need to know about throbbing pain in the knee at night.

There is no one single medical condition that causes throbbing knee pain at night. The throbbing pain of the knee usually stems from a wide variety of musculoskeletal disorders or injuries. Due to this, your doctor is likely to consider many potential causes.^{(1, 2)}

Some of the most common causes of throbbing knee pain during the night include:

• Runner’s knee
• Bursitis
• Osteoarthritis
• Injuries

Some of these conditions, such as runner’s knee, get better after you give the required amount of rest to the knee. However, other conditions, like osteoarthritis, are long-term illnesses that tend to get worse with time.^{(3, 4)}

Once your doctor determines the actual cause of your pain, they will put you on the appropriate treatment to relieve the pain.

Here’s a closer look at the reasons for throbbing knee pain at night.

1. Runner’s Knee

   Runner’s knee is the most common cause of throbbing knee pain in athletes. If you have a runner’s knee, you are likely to feel a throbbing pain behind your kneecap. Many people with runner’s knee report having similar symptoms, including radiating or dull pain near the knee. You may also feel a grinding sensation near the kneecap.^{(5, 6, 7)}

   It won’t be incorrect to say that runner’s knee is more of an umbrella term that refers to this type of knee pain. The actual causes behind this type of knee pain can be many, including overexertion of the knee due to jumping instead of running. Some people are also more likely to develop runner’s knee because their kneecap might not be in the right position to protect and cover the knee joint correctly.

   In most cases, people with runner’s knee find that their symptoms alleviate or go away after a few weeks of rest and avoiding any kind of strenuous activity. If you experience moderate to severe pain, you can even take some over-the-counter pain relievers as needed to manage the pain.

2. Bursitis

   Bursitis is a condition that causes painful inflammation over the kneecap or on the sides of the knee. There are tiny sacs filled with fluid in the knee that is responsible for letting the tendons move smoothly over the joints. These small sacs of fluid are known as bursae. In bursitis, these sacs of fluid become swollen, causing knee pain.^{(8, 9)}

   Similar to the runner’s knee, bursitis can happen in many different ways. The most common cause of this condition is when you put too much of pressure on the knee, like while squatting or kneeling, without wearing braces or knee pads for support. Sometimes a bursa can also get swollen after hitting your knee during trauma or injury.^{(10, 11)}

   Bursitis can also be caused by overexertion, though it is a less common condition than a runner’s knee. This condition presents many symptoms apart from radiating pain in the knee and swelling.

3. Osteoarthritis

   Unlike the moderate cases of the runner’s knee, the symptoms of osteoarthritis are not temporary. Osteoarthritis is a long-term disease that tends to progress and get worse over a period of time. This is why it is important to consult your doctor to come up with a long-term treatment plan.

   In a normal, healthy knee, the soft tissue that includes cartilage provides cushioning to the three bones of the knee. These tissues act like shock absorbers that support your body weight when you walk, run, or fall. The cartilage of the knee helps the knee bend without the bones touching and scraping against one another. However, in a person with osteoarthritis, these soft tissues get damaged and degraded due to wear and tear. This causes the bones in the knee to begin rubbing against one another, which causes inflammation, irritation, and pain.^{(12, 13, 14)}

   It is important to know that there is no cure for osteoarthritis because there is no way that the damaged or eroded joint tissue can be repaired or replaced completely. However, there are many treatment options available for people with osteoarthritis that help reduce the pain and also prevent further damage to the knee joint.

   Pain caused by osteoarthritis feels like aching, throbbing, stiffness, and radiating from the knee. These symptoms tend to worsen at night as osteoarthritis pain tends to flare up during periods of rest.⁽¹⁵⁾

4. Knee Injuries and Other Conditions

   Since the knee is the biggest joint in the body, it is more prone to injuries and stress. If you fall and bump your knee, you may experience some bruising and pain. If you fracture any of the three bones in the knee, you will experience sharp pain, deep throbbing pain, and weakness of the knee.^{(16, 17)}

   Similarly, rheumatoid arthritis can also cause similar symptoms to osteoarthritis. However, rheumatoid arthritis is an autoimmune condition, and it requires different treatments than the ones used for joint damage caused by normal wear and tear.^{(18, 19, 20)}

Most knee conditions that cause radiating pain, such as bursitis and runner’s knee, tend to improve by themselves after you rest the knee for a couple of weeks. However, most people find that the knee pain becomes progressively worse at night.⁽²¹⁾ There are several reasons behind this.

The Body Relaxes At Night: When the body is resting, you are more likely to notice even the mild to moderate pains that you ignored during the day when you were working, or your mind was preoccupied. Furthermore, when you sleep, the production of cortisol in the body is reduced. Healthy levels of cortisol help your body decrease inflammation, though high cortisol levels can cause heart disease. Most joint pains are caused by worsening inflammation. In such cases, moderate amounts of cortisol help the body manage inflammation. However, when the body is at rest and relaxed, such as when you are trying to sleep at night, the body has lesser levels of cortisol available to continue to mitigate the irritation and swelling in the knees, thus making you feel the pain more.⁽²²⁾

Lack of Sleep: Radiating knee pain at night can easily lead to a vicious cycle of not being able to sleep. And the worst part is that this lack of sleep can actually worsen your pain. Sleep is crucial for the body to heal and rejuvenate. When you don’t get proper sleep, you have less energy to spend on healing as the body needs to conserve that energy to stay awake and alert. It is important to remember that if you keep tossing and turning at night due to your knee pain, you may actually end up accidentally hurting yourself further by straining your knee, especially if you fall asleep in an uncomfortable position.⁽²³⁾

Waking up Stiff: When you sleep at night, the body is at rest and rejuvenating itself. However, the hours you spend laying down can also cause your joints to feel less flexible and stiff when you wake up. Though overexertion can lead to knee pain, a little amount of physical activity is still needed to keep the joints healthy. Try practicing some low-impact activities like walking, yoga, or swimming to increase the flexibility of your joints. Such types of movements can help your tendons remain more flexible and help circulate fluid that provides lubrication and also protects your knee joints.⁽²⁴⁾

The exact treatment for your pain will depend on the exact nature of your injury or knee condition that is causing the pain. To manage the pain, your doctor is likely to recommend certain pain reliever medications, lifestyle changes to help you sleep better, applying heat and ice packs, and lots of rest for the affected knee. Alternate therapies like acupuncture can also help you cope with mild to moderate pain, especially if it is being caused by arthritis.

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