In heart disease, what's a clot and what's a clog?

Cardiologists can help you to keep your heart clear of clots and clogs. See more heart health pictures.
Cardiologists can help you to keep your heart clear of clots and clogs. See more heart health pictures.
Hans Neleman/Getty Images

Your heart is an 11-ounce (312-gram) powerhouse that beats ceaselessly even before birth until you take your very last breath [source: Franklin]. It's an amazing and tireless worker, making sure that spent blood arriving from your body returns to the lungs for oxygen, while simultaneously sending newly oxygenated blood back out to the rest of the body.

Over the course of your lifetime, your ticker may beat as many as 3.3 billion times [source: Roizen]. With each beat, chambers are contracting and relaxing, valves are opening and closing, and more than a gallon of blood (3.8 liters) is passing through your heart each minute [source: Bianco].


There's a lot going on in that fist-sized pump. Keeping it humming along requires some maintenance in the form of exercise, good diet and regular medical checkups. Without some tender loving care, your heart can become diseased and lose its ability to function at its optimal level.

Despite our best intentions, sometimes genetics or bad health decisions made when we were younger lead to problems such as coronary artery disease and heart attacks, both of which are the results of clogs and clots. No matter how often these words are thrown at us in discussions on heart health, their exact meanings never seem to stick. Are clogs and clots the same thing? If not, how do they differ, besides on that one letter? Do both lead to heart attacks? Can you have one without the other?

Frankly, neither clogs nor clots are much fun. But with a little knowledge and regular maintenance, the only clots and clogs you'll encounter are when your kitchen sink backs up. In this article, you'll learn what each one is, what they do and where they come from. Continue to the next page, and we'll begin sorting this out by looking at the slower of our two unwelcome guests in the heart -- clogs.




Coronary Clogs: Slow Strangulation

A coronary artery with atherosclerosis, indicated by the yellow mound on the bottom wall of the blood vessel
A coronary artery with atherosclerosis, indicated by the yellow mound on the bottom wall of the blood vessel
3DClinic/Getty Images

Unfortunately, clogs aren't just wooden shoes worn by Dutch school children. The word also refers to the buildup of plaque inside your coronary arteries, the main pipelines that deliver oxygen-rich blood to your body.

Your arteries have three layers: a protective outer casing (the adventitia), a muscular middle layer (the media) and a thin, smooth inner layer (the intima), which allows blood to slide through to its destination. Like a finished wall in your home, this smooth inner layer suffers wear and tear. With a constant blast of blood pushing through these arteries, the inside lining is banged up from things like nicotine, natural minerals such as calcium and low-density lipoprotein (or LDL) cholesterol. High blood pressure also increases the force exerted against the arteries' inside lining, scuffing it up.


All these nicks, dings and chips may leave the middle arterial layer vulnerable to damage by exposing it to the bloodstream. To avoid that scenario, your body has several mechanisms for patching up these nicks, one of which is filling them with a spackle consisting of platelets, white blood cells and cholesterol.

It's not­ a perfect process, though. The infection-fighting white blood cells mean well, but they track toxic materials into the work zone, so the inner lining becomes more irritated, and the hole starts spreading. As this happens, more plaster is being used to fill the hole, more impurities are latching on, more white blood cells show up and the cycle continues, leading to bigger blockages. These blockages that harden the arteries are better known as clogs. In addition, the artery narrows, leading to even higher blood pressure as your heart tries to force blood past the coronary clogs.

As your arteries clog over many years, they stop being soft and supple and instead stiffen like an old garden hose that's been left too long in the sun. This worsening buildup of plaque and consequent hardening of the arteries is known as atherosclerosis, and it can limit the amount of blood reaching your heart. If your heart can't get the blood it needs, you may start feeling a chest pain called angina. This slow starving of the heart also drains you of energy and, not surprisingly, affects your quality of life.

By exercising and eating right, you can increase the amount of high-density lipoprotein (HDL) cholesterol in your body. HDL cholesterol is considered good because it can remove some of the plaque in the form of LDL, or bad, cholesterol from your clogged arteries. (To learn more about the different types of cholesterol, read What's the difference between LDL and HDL cholesterol?) Exercise also helps to lower blood pressure, which will relieve some of the burden on your troubled arteries. However, statin medications or more serious surgical measures, such as angioplasty, bypass surgery or stenting, may be needed to fix or bypass these clogs, .

As bad as coronary clogs are, they just lay the groundwork for something that can be even more dangerous: clots.


Coronary Clots: Fast-Acting Total Eclipse of the Heart

A heart attack, courtesy of a blood clot in a coronary artery
A heart attack, courtesy of a blood clot in a coronary artery
HowStuffWorks 2008

Sometimes, when clogged arteries are cleared -- either naturally or medically -- a larger problem presents itself: a clot. Picture the pipes beneath your kitchen sink: Inside them, there's probably some gunk that has built up in certain spots (a clog). As this gunk gathers in the pipes, the water passing over it firms up the outer layer. As a deposit in one area grows, it attracts more of your kitchen-sink drainage and food matter to it. Eventually, the water pressure increases on this trouble spot, and water wears away the gunk and knocks it free (a clot).

A similar scenario can unfold in your arteries, and it can start with the clogging process we just talked about. When an unstable piece of that clog breaks free, it leaves a nick in its surface Just as your body quickly works to repair a cut on your skin with a scab, it also hustles to repair the nick on that clog. We call this scab forming inside your artery a clot, and it can shut down blood flow to your heart or brain within minutes, causing you to have a heart attack or stroke.


Before you take an aspirin to help prevent further clotting, in fact, before you do anything, call 9-1-1 [source: AHA]. The faster you get yourself into a doctor's care, the better. If you get medical treatment within an hour or two, doctors will have a better chance of saving damaged heart tissue.

Once you get to a hospital, doctors may inject a clot-busting medication such as streptokinase or tissue plasminogen activator (TPA) to break up the clot. They also may insert a balloon catheter to dilate the narrowed artery (called angioplasty), and a stent, a small tube made of metal or plastic, to stabilize the artery.

­Now that you know more about coronary clots and clogs, you may find yourself lying awake in bed, overwhelmed by clog and clog anxiety. It's a valid concern, but a heart healthy lifestyle will help to prevent clogs and clots from forming. A doctor may advise you take a daily aspirin to help prevent heart attacks and strokes if you're susceptible to clotting due to heart disease or other conditions. And if you feel chest pain, tingling, pain in your legs or signs of stroke such as difficulty speaking or numbness, seek immediate medical attention.

If you still can't sleep, why don't you wander over to the next page for more stories on your heart.



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More Great Links


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