It is not completely abnormal, but if the pain is intense while you're just casually walking or if you're worried about it you should have it checked out.
There are lot of resources available online which have information on knee pain causes, treatments and how to manage knee pain in long term. There are websites like ehow.com or coolrunning.com which are good resources for information on knee pain with running.
Being overweight does and can lead to knee pain while running. It also leads to knee problems if you do not change your life style. Either if you are overweight or a health weight and have knee pain you should consult a doctor.
Some of the possible causes of knee pain with running include poor footwear, not stretching before the run, and not taking adequate precautions if there is knee pain. Swelling is a common symptom associated with knee pain and can be reduced using pain medications.
Here is a site for you to look at unitedrunners.org/injuries/knee-pain-while-running-there-is-a-solution . However knee pan does not mean you have to stop exercising there are other exercises you can do until your knee feels better.
You can prevent knee pain or injury while running by doing exercises before you run this can help in pains. Here is a site on just that information www.drbookspan.com/KneePainArticle.html
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It can be dangerous. It's best to go see a doctor to have them diagnose if the knee pain is dangerous or not, or if you can continue running. It could be something minor, or it could require surgery, it's best not to continue running with a bad knee because if you damage your knee you're pretty much helpless as the knee takes a lot of abuse in everyday activities.
Wearing corrective shoes, or proper running shoes will definitely assist in treating knee pain from running. You can try to relieve this pain with ice packs and taking an anti-inflammatory. If it does not improve over a few days you should seek further medical attention.
First, knee pain can be caused by many different things, before you start taking medication, you should go to the doctor and find out the cause of the knee pain. There are also some over the counter drugs for knee pain at any drug store or pharmacy.
One of the best things you can do for short term knee pain is actually to avoid exercise and focus on rest, heat and ice. If your pain is relieved by that and you give it about a week you can start to build up to normal exercise from something like an elliptical which is low impact to something like running which is high impact.
Barefoot running is not a good way to perfect your technique. Barefoot running can lead to shin splints, achilles tendon pain, knee pain and arch pain.
A lot of people do get knee pain while running, due to various reasons being lack of circulation, joint deterioration, calcium build up or lack of endurance being done on the knee. It is important to rest when you feel the pain, as you may cause permanent injury.