Bruises probably aren't something you typically give much thought. You might bump into a low table while you're walking through your house, and think, "Ouch, that's going to be a nasty bruise tomorrow." Or maybe you wake up in the morning, notice a
purplish-blue mark on your elbow, and think, "Wow, how did this happen?" and then immediately proceed to forget about it. That's because bruises happen to all of us, and they usually aren't a big deal. But the truth is that sometimes bruising can be the sign of a larger health condition that you need to get checked out — and it's important to know how to tell if it is.
In general, a bruise is basically
a form of internal bleeding. It's usually caused by some sort of trauma (a bump, a fall, etc.) that makes the blood vessels under your skin tear. When that happens, the blood leaks into the surrounding tissues and clots, which results in that black and blue mark you see on your skin. Some people bruise pretty easily, and that's not necessarily a sign of something larger. I, for example, wake up with bruises quite often, with no recollection of how they got there (I am extremely clumsy). Others don't bruise as easily. It's usually as simple as that!
There are some cases where it isn't that simple, though. It's rare for bruises to be a sign of something more serious, but it can and does definitely happen. Here are a few signs your bruises are part of a larger health condition:
1 Your Bruises Look Like A Rash
If you notice tiny bruises all over that look more like a rash, that could be purpura.
Purpura is also known as blood spots or skim hemorrhages, and it's a series of purple-colored spots that can look similar to bruising. It occurs when small blood vessels burst, which cause blood to pool under the skin, creating those purple spots. They can range from tiny dots to large patches, and they can occur on your skin or even on the inside of your mouth. Purpura spots can be nothing, but they could also be indicative of a serious medical condition like blood clotting disorder, which is why they're worth getting checked out. 2 Your Periods Are Very Heavy
Bruising easily is a common affliction. But if you bruise
very easily, experience excessive bleeding during an injury, or have super heavy periods, you could have Von Willebrand disease. It sounds scary, but it's actually the most common hereditary coagulation abnormality in humans, so it's quite common.
Von Willebrand disease (VWD) is a genetic disorder, and it basically means that you are missing or have defective von Willebrand factor (VWF), a clotting protein. Without VWF, your blood doesn't clot normally, which can be why you're bruising and experiencing heavy periods. If you suspect you have this, you'll need to see a doctor for a diagnosis.
3 There's Significant Swelling
If you notice that your bruise is accompanied by a significant amount of swelling and pain, you might want to get it checked out. Sure, it could just be because you fell badly or really bumped into something hard, but Dr. Monique Tello, a primary care physician at Massachusetts General Hospital, says it could also be a sign of a
larger bleed under the skin. This is especially true if your bruise was caused by a fall or some other sort of injury.
A small amount of swelling when a bruise begins is normal, but if the pain and swelling won't go down hours after the injury, you should see a doctor. You'll want to make sure you aren't bleeding internally.
4 Your Bruises Get Larger Over Time
Bruises tend to go through stages. You might notice that your bruise gets larger before it gets better, which is fairly normal, especially if you had a very bad injury. But if it just continues to get larger and doesn't seem to be getting any better after two days or so, it could also be a hematoma that could continue to bleed. According to
VeryWell, a hematoma is a "collection of blood outside of a blood vessel" and are caused by injury to the wall of a vessel. Some are harmless, while others are a little more dangerous.
The difference between a regular bruise and a hematoma is that hematomas are larger bleeds that can collect so much blood that it can lead to low blood pressure and shock. And if they're really big, hematomas can even cause organ dysfunction, and might require surgery.
5 You Notice Bruises In Unusual Places
Since bruises typically happen from some sort of injury or mishap, you're most likely to see the "normal" ones on places like your back, your legs, your arms, and your abdomen - you know, spots where you bump into something or hit if you fall on the ground.
But if you notice bruises in unusual spots, like your joints, that could be the sign of a bleeding disorder or even Rheumatoid arthritis. According to
Everyday Health, Rheumatoid arthritis can "cause your blood platelet count to dip below the normal level." Because of this, your body can't replace the platelets as quickly as they're being used, and that can mean you bruise more. If you have other symptoms of RA, it's worth bringing it up to your doctor. 6 You're Always Thirsty
If you bruise easily and often, and also experience symptoms like excessive thirst, blurred vision, and fatigue, you might want to head to a doctor — all of these symptoms combined could be a sign that you have diabetes, specifically type 2 diabetes.
VeryWell, diabetes can disrupt circulation because the blood is so thick with sugar. If your circulation is off, that can make it harder for blood to get where it needs to go, which means that your body can't heal wounds as easily. That results in bruising. If you notice that your cuts and bruises are taking an unusually long time to heal (along with other diabetes symptoms), you may want to mention that to your doctor. 7 Your Bruises Look Like Tiny Dots
Do your bruises look more like tiny black and blue dots instead of straight up blotchy, large bruises? If so, it could be something called
petechiae, which happen when tiny capillaries break. These little purple, red, or brown spots resemble teensy bruises and can be found anywhere from your neck, arms, stomach, and even in your mouth. The dots also tend to look more like a rash when it's actually bleeding under the skin.
Petechiae can be a reaction to certain medication, or it a sign of something more serious. If you're unsure of what the rash-like bruising on you is, try pressing on them - petechiae won't turn white when pressing on them, while a rash would.
8 You Have Swollen Gums
Scurvy might sound like something that only happened to pirates back in the day, but that's not the case. People can still get scurvy, and you definitely don't need to be at sea for it to occur. Scurvy is caused by a vitamin C deficiency, and while there are many symptoms, one of them is a lot of bruising. According to
Healthline, you may notice skin hemorrhages (which is bleeding under the skin), large reddish-blue to black bruising that usually occurs on legs and feet, and bruise-like raised bumps at hair follicles.
Other symptoms of scurvy include tooth decay, swollen joints, shortness of breath, chest pain, dry eyes, and blurred vision. If you're experiencing a lot of these along with weird bruising, see a doctor.
9 You Notice Small Red Dots
Bruising can sometimes be a sign of cancer — it's rare, but it happens. Specifically, it could be a sign of
leukemia, or another blood, bone marrow, or lymph node cancer. The bruising that accompanies leukemia can look very similar to regular bruises. The difference? There will be a lot of them, and you won't really be able to explain where they came from.
But leukemia bruising can also look like little red dots - remember the petechiae discussed above? Those red, rash-like dots can also be a sign of leukemia.
10 You Bruise Very, Very Easily
Bruising easily is common, especially if you're a particularly clumsy person who is always bumping into everything. But there's a difference between bruising easily when you bump around a lot, and bruising excessively.
Excessive bruising can be a sign of a clotting disorder called
thrombocytopenia, which causes a low blood platelet count. Platelets are responsible for clumping up and forming a plug when blood vessels are injured, and a lack of them will make you bruise very often. This disorder often doesn't come out of nowhere, but instead happens because of another disease or condition, such as leukemia, or it could even be a side effect to certain medications. 11 This article was originally published on May 6, 2018 and was updated on September 5, 2019.