When you have diabetes, you tend to keep a close eye on your overall health, which means you'll notice a problem such as severe arm bruising more readily. Several diabetes-related problems and conditions can contribute to arm bruising, including necessary insulin injections and diabetic kidney disease. In addition, you might mistake a condition called acanthosis nigricans for bruising; this pigmentation disorder appears fairly commonly in diabetics. If you're in doubt about what's causing your problem, you should see your physician for a complete checkup.
Insulin Injections
All type 1 diabetics and some type 2 diabetics inject themselves with insulin every day to keep their blood sugar level stable. Insulin absorbs best from areas where there's a fair amount of fat directly below the skin, and many people inject themselves in either their abdomens or their upper arms. However, using the same location over and over for your insulin injections can cause swelling and bruising in that area, making insulin injections a potential cause of severe arm bruising in diabetics. If bruising results from repeated insulin shots in one place, try to vary the location of your shots. In addition, if you find you're bleeding following your injection, you might be injecting the insulin into your muscle instead of fat tissue. Again, try a different location.
Kidney Disease
Regardless of whether you use insulin to treat your diabetes, your severe arm bruising might represent a sign of another diabetes-related condition: diabetic kidney disease. Kidney disease that's related to your diabetes presents few real symptoms until it's far advanced; you might feel more tired, or find your skin itches, or you might have no symptoms at all. However, severe bruising on your arm or elsewhere might indicate low iron levels, which can be a sign of kidney disease. Your doctor likely will want to run some blood tests to determine your kidney function. If you do have diabetic kidney disease, your doctor can help you make dietary changes that should help control your condition.
Acanthosis Nigricans
In some cases, discoloration that looks like bruising on your arm might not be a severe arm bruise at all. Instead, it might be a sign of acanthosis nigricans, a condition involving skin discoloration related to diabetes. In acanthosis nigricans, patches of brown or black skin appear on your body, usually in your armpits or on your neck, due to excess insulin circulating in your body. Your doctor can tell the difference between a severe arm bruise and acanthosis nigricans, so if you're not sure what you have, you should schedule an appointment. Keeping your blood sugar under control might help clear up the skin discoloration.
Considerations
Diabetes itself doesn't usually cause bruises, but the condition can make existing bruises last longer and heal more slowly. If you experience frequent, slow-to-heal bruises along with other potential symptoms of diabetes, which can include frequent urination, thirst and extreme hunger, fatigue and unintentional weight loss, you should see your doctor and ask to be screened for the condition. If you catch diabetes early, you potentially can avert some or all of the condition's serious complications, including heart disease and kidney disease.
