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Pinching your arm can cause blood vessels to break, leading to bruises. While it may appear red and swollen at first, your arm may turn a blue or purple color as the bruises start to appear. Most bruises heal on their own, but may cause discomfort in the process. If your arm stays blue and bruised for an extended period or causes excessive pain, make an appointment with your physician. She may want to evaluate your injury for other complications.


Several types of bruises can cause skin discoloration. Both intramuscular and periosteal bruises, which occur in the muscle and bone respectively, happen when blood vessels break after an injury. Subcutaneous bruises, which are common, affect the skin and occur when surface-level vessels break. Pinching your skin may cause this type of bruise. Bruises can make your arm turn into an array of colors. It may appear red at first and then transition into a purple or blue color.


Whether you pinch your skin between two fingers, fall asleep with your head on your arm or squeeze your arm into a tight-fitting area, applying pressure to your skin can lead to bruising. Pinching your arm causes blood flow to stop or slow down. Harsh pinching or pinches that last for an extended period might cause blood vessels to break. Additionally, as you age you may be more susceptible to bruising easily. Older thin skin and capillaries can bruise easily, even from the slightest pinch. Blue and purple bruises typically heal on their own, but you can take certain measures to help the healing process.


Icing the blue bruise helps with healing and swelling. Place several ice cubes in a plastic bag and wrap in a rag. Keep the ice pack on the pinched area for 15 minutes and repeat every hour if needed, suggests MedlinePlus. Lift your arm above your head, if possible. Keeping your pinched arm above the heart prevents blood from flooding into damaged tissue. Rest your arm as much as possible while it heals.


Scleroderma is a type of condition that causes abnormal issues with skin and connective tissues. One specific type of scleroderma, called Raynaud’s phenomenon, causes your skin to turn blue. Factors affecting normal blood flow, such as pinching, extreme cold, anxiety or a combination of issues, cause blood vessels to contract. When this happens, your arms and hands may turn white and then blue, since blood flow slows down. If your hands stay blue for an extended period, your fingertips may become damaged, causing gangrene or ulcers, explains the National Institute of Arthritis and Musculoskeletal and Skin Diseases. Avoid permanent damage by seeking medical attention if your arm stays blue for an extended period.