Has your kneecap moved out of position (dislocated)?

Does your knee look twisted, bent out of shape, or out of its normal position after a recent injury?

Is your knee cut or scraped and you think you have broken or dislocated it?

Did your knee pop, move, or get pulled out of its normal position and then return to its normal position?

If you have answered "No" to the above questions, go back to Check Your Symptoms and continue to answer the questions to evaluate your symptoms.

Do you have severe pain?

Is a young child unable to walk or carefully protecting his or her knee after a known or suspected injury?

Do you have pain with swelling or bruising that began within 30 minutes of an injury?

Do you have moderate pain that is getting worse?

Do you have moderate pain that has not gotten better after 24 hours of home treatment?

Does moving or bending your knee still cause mild pain after 48 hours of home treatment?

Have you had intermittent mild pain without other symptoms for 2 weeks?

If you have answered "No" to the above questions, go back to Check Your Symptoms and continue to answer the questions to evaluate your symptoms.

Do you have knee pain and your lower leg or foot is pale, white, blue, or cold?

Did your lower leg or foot turn pale, white, blue, or cold after you had a splint or cast applied? Note: See first aid for a cast or splint that may be too tight.

If you have answered "No" to the above questions, go back to Check Your Symptoms and continue to answer the questions to evaluate your symptoms.

Do you have knee pain with numbness or tingling in your knee, lower leg, or foot?

Have you had knee pain with steady numbness or tingling for 1 hour or longer?

Do you have new numbness or tingling, and the skin below your knee is pale, white, blue, or cold?

Are you unable to move your knee normally (not because of pain or because a splint is in the way)?

Is numbness or tingling getting worse?

Have you have steady numbness or tingling below your knee for 1 hour or longer, but you do not have other symptoms?

Have you had numbness or tingling that comes and goes during the past 24 hours?

If you have answered "No" to the above questions, go back to Check Your Symptoms and continue to answer the questions to evaluate your symptoms.

Do you have severe pain?

Has a lot of swelling developed within 30 minutes of an injury?

Does your knee look twisted or bent out of its normal position?

Is your knee so unstable that you cannot stand or walk (bear weight)?

Did your knee suddenly give out or buckle, but it seems all right now?

Has your knee felt unstable for a long time, but you have never had it checked by a doctor?

Has your knee felt unstable for a long time, and the problem has gotten worse since you had it checked by a doctor?

If you have answered "No" to the above questions, go back to Check Your Symptoms and continue to answer the questions to evaluate your symptoms.

Is the skin below the swollen area cold or pale?

Has a lot of swelling or bruising developed within 30 minutes of an injury?

Have you had new swelling in the back of your knee for longer than 48 hours?

Do you have moderate swelling after 48 hours of home treatment?

If you have answered "No" to the above questions, go back to Check Your Symptoms and continue to answer the questions to evaluate your symptoms.

Do you have severe pain?

Has a lot of swelling developed within 30 minutes of an injury?

Does your knee look twisted or bent out of its normal position?

Are you unable to stand or walk (bear weight)?

Did you feel or hear a snap, pop, or grinding, but you do not have other symptoms?

Did you feel or hear a snap or pop, and your knee has given out or feels like it will buckle?

Have you had a grinding sensation in your knee, but you do not remember a specific injury?

If you have answered "No" to the above questions, go back to Check Your Symptoms and continue to answer the questions to evaluate your symptoms.

Do you have severe pain?

Are you unable to straighten or bend your knee?

Are you unable to move your knee normally because of muscle weakness (not just because of pain)?

Is a young child carefully protecting a knee or unable to walk after a known or suspected injury?

Are you unable to move your knee normally or do you have decreased strength after 48 hours of home treatment?

Does your knee lock from time to time, but it is not locked now?

If you have answered "No" to the above questions, go back to Check Your Symptoms and continue to answer the questions to evaluate your symptoms.

Do you think that a knee injury may have been caused by abuse?

If you have answered "No" to the above questions, go back to Check Your Symptoms and continue to answer the questions to evaluate your symptoms.

Do you have increased swelling, redness, or warmth around your knee?

Do you have severe pain with movement of your knee?

Do you have red streaks extending from your knee?

Does it hurt to touch your knee?

Do you have drainage of pus from your knee?

Do you know or think you have a fever?

Do you have diabetes?

Do you have peripheral arterial disease?

Do you have a disease or take a medicine that causes problems with your immune system?

Have you had mild pain and swelling with redness less than around the injured area for 24 hours?

Have you had swollen lymph nodes in the groin for longer than 48 hours?

If you have answered "No" to the above questions, go back to Check Your Symptoms and continue to answer the questions to evaluate your symptoms.

Did a large (the size of the injured person's palm), painful, swollen bruise develop within 30 minutes of an injury?

Do you think you bruise too easily?

Have bruises from an injury lasted longer than 2 weeks?

If you have answered "No" to the above questions, go back to Check Your Symptoms and continue to answer the questions to evaluate your symptoms.

Call your health professional immediately.

You have answered "Yes" to a question that indicates you may need immediate care. Call your health professional now to discuss your symptoms and arrange for your care.

• Symptoms are likely to worsen without medical care.
• If you do not have a health professional, seek emergency care.
• Emergency transportation is not needed. However, if you are not able to travel safely either by driving yourself or having someone else drive you, call an ambulance.

You do not need to answer any of the other questions.

Call your health professional today.

You have answered "Yes" to a question that indicates you need to call your health professional to discuss your symptoms and arrange for care.

• An appointment today is usually needed.
• Symptoms are unlikely to improve without medical care.

Return to the Check Your Symptoms section and answer the questions. You may need to see a health professional sooner if you have other more serious symptoms.

You may wait to see if the symptoms improve over the next 24 hours.

You have answered "Yes" to a question that indicates you may wait to see if your symptoms improve over the next 24 hours (or the specified time period). If symptoms improve, no appointment is needed.

• If symptoms do not improve after 24 hours (or the specified time period), an appointment within the next 24 hours is usually needed.
• If appropriate, try home treatment to relieve your symptoms.
• Check your symptoms in 24 hours, or sooner if there is any change.
• Call your health professional if symptoms get worse.

Return to the Check Your Symptoms section and answer the questions. You may need to see a health professional sooner if you have other more serious symptoms.