Do I Have A Purple Eye?

My son has a wooden toy axe that he bought with his allowance money when we went to the Ohio Renaissance Festival. This will be an important fact, momentarily.

Last week, we were roughhousing in his room. That ridiculous sort of “wrestling” you do with your kids, that’s mostly the kid jumping on you and climbing all over you and laughing hysterically. Both of us were having a good time, even though I had to remind him that he shouldn’t actually hit me with the axe. He tells me he’s sorry, then jumps on my back and slides around and goes face-first onto the floor. I’m not concerned, because he does this about once a minute when we’re roughhousing.

Then he shouts “ouch!”

Being a dad who tries hard to be a good dad, I immediately check to see what’s going on. He has, it seems, landed face first not on the floor but on the axe handle. When he comes up, he’s rubbing his eye. Then he moves his hand. “Do I have a purple eye?” he asks.

I look. “No. You’re all right.”

He nods, rubs his eye one last time, and then tackles me.

What is a bruise?

Clearly, he didn’t get significantly hurt. The pain went away quickly, and no bruising developed. But that got me thinking. I’ve had bruises before, but I’ve never really been sure what they are. I know they’re caused by impacts, and I’m pretty sure they involve bleeding beneath the skin, but that hits the limits of my knowledge. So even though he didn’t ask a direct question along the lines of “what’s a bruise?”, I decided to look into the question.

Advanced Tissue defines a bruise as “a condition in which small blood vessels under the skin rupture, causing blood to leak into the underlying skin tissue.” Which makes me feel good, finding out that my received wisdom (probably from my parents, but I couldn’t say for sure) is correct. But then the definition goes on to note that “there are three common types of bruises that can occur based on the severity of an injury: contusions, hematomas, and purpura.”

Now I’m intrigued. I’ve heard the word ‘contusion’ before, and just assumed it was a synonym for a ‘bruise’. I’ve also heard the word ‘hematoma’, and recognize just enough Latin to know that it must involve blood, but I don’t know what one is. And ‘purpura’? Well, let’s just say my first guess would have been “that’s the intermediate lifecycle state of a butterfly, right?”. And then I’d have acknowledged that I’m entirely wrong.

So, a contusion is the most common type of bruise, caused by “blunt force trauma” – that is, hitting yourself. If the impact is strong enough to damage blood vessels, a contusion forms. The skin under the impact site will turn colors; red at first, then black, blue or purple, then possibly green and yellow as the blood breaks down and is reabsorbed by the body.


A hematoma is ” a type of bruising where a massive collection of blood has pooled at the injury site”, and is often accompanied by greater pain and swelling. They can be caused by the ever-popular ‘blunt force trauma’, by spontaneous rupturing of blood vessels (and I’m just a little on edge knowing that “spontaneous rupturing of blood vessels” is a thing), or by surgical procedures. They can be dangerous if they occur in or near vital organs.

Purpura are smallish bruises, generally resembling purple-colored patches or spots – that occur when small blood vessels rupture. Most frequently, these aren’t caused by our good friend blunt force trauma; they are typically the result of certain diseases, aging (which makes the blood vessels more fragile), and some drugs that reduce platelet count. Why that latter? Because platelets are instrumental in the clotting process, which helps seal damaged vessels. If they’re slow to seal a small rupture in a small vessel, for example because the platelet count is low, a purpura forms.

How do you treat a bruise?

Generally, bruising is initially treated with the “RICE method”. RICE, in this context, is an acronym that stands for Rest, Ice, Compression, and Elevation. For the first 24 to 48 hours you should take it easy on the injured area, put ice and pressure on it (to reduce swelling), and keep it elevated if at all possible (which reduces the blood flow, which also reduces swelling). After that initial 24 to 48 hour period, light to moderate exercise of the muscles and joints near the bruise will help with healing. And be certain to consult with your doctor if it seems especially severe or painful, or if it doesn’t seem to be healing. I’m a stock broker, not a doctor. Don’t depend on me for your health care, please.

Oh, and there’s this statement from Advanced Tissue: “Unlike contusions and hematomas, purpura treatment will vary on a case-by-case basis as determined by a medical professional by evaluating the underlying cause of the purpura.”

Wait… bone bruise?

Yes, I know that I didn’t actually say anything about the hideous-sounding ‘bone bruise’. But it came up in the “Treating a Wound or Bruise” information I was reviewing. The very phrase makes me cringe and makes my skin crawl, so I now have a powerful need to find out what it is in hopes of reducing that reaction. I’m weird that way – as a child, I had to watch my doctor give me shots and draw blood in order to reduce my fear of getting stuck with a needle, too.

Physopedia defines a bone bruise as:

Bone bruise is one of the four types of fractures that occur in the human body, the others are: stress fractures, osteochondral fractures and bone fractures.

Bone bruise is a term that contains 3 different kinds of bone injuries: sub-periosteal hematoma, inter-osseous bruising and sub-chondral lesion.

A bone bruise can be described as a stage before the fracture.

When we speak of a real bone fracture it means that all the bone trabeculae of that specific place are fractured. In case of a bone bruise only a few of the trabeculae are broken.

None of that is reducing my urge to cringe. Let’s dig deeper.

The periosteum is the layer of connective tissue that covers a bone. If you’ve ever gnawed on a chicken leg or pork chop bone, and found yourself stripping off a thin transparent layer from the bone, that’s the periosteum. (Please tell me I’m not the only one who’s ever done that…) It’s actually two layers. The outer layer is tough collagen and fibroblasts (which produce more collagen), and the inner layer is stem cells and osteoblasts (which help repare the hard part of the bone if its damaged). So, that first type of bone bruise – the sub-periosteal hematoma – is caused by rupturing the blood vessels immediately beneath the periosteum – hence the name. This type of bone bruise is the direct result of our old friend blunt force trauma.

Inter-osseous bruising, the second form of bone bruise, is damage to the blood vessels that penetrate the bone itself. why do we have blood vessels penetrating our bones, you ask? Because our bones contain marrow, a spongy cellular factory for new blood cells. Which makes marrow extremely important, as you may guess, and which also means that we need a way to move them out. Well, “repetitive high compressive force on the bone (extreme pressure on regular base)” can rupture those vessels, causing blood to pool inside the bone itself. Yes, my skin is crawling again.

Sub-chondral lesions are bone bruises that occur beneath the cartilage layer of a joint – the padding that protects bone where it meets other bone. “The main trigger is an extreme compressive force that literally crushes the cells, that results in a separation of the cartilage (or ligament) and the underlying bone, plus bleeding when the energy of the impact extends into the bone. The other trigger is a shearing force, it sustains from a rotational mechanism such as twisting and translational forces. These will also cause that the cartilage tissue will be stripped away and exposing the underlying bone. It results in the same injury as a compressive force injury but this is another source of the injury.”

Yeah. Not better.

Bone bruises don’t show up on x-rays unless there is an associated fracture, so diagnosis can be difficult. Treatment generally involves rest and avoiding repetitive and strong loads on the bruised bone, and plenty of rest. You should really see your doctor, if you think you have one of these.