A disease is a condition in the body that disrupts normal functions.
Why are some diseases contagious while others aren’t? This lesson discusses the difference between communicable and noncommunicable diseases.
What Are Diseases?
Let’s say you’re sitting at a gate in a major American airport, waiting to board a flight. At a neighboring gate, a flight arrives and several people exit the plane wearing surgical masks. You assume that you should probably avoid these people. They must have some illness and are trying not spread it to a planeload of people.
Then, your plane starts loading. You strike up a conversation with someone who’s describing their difficulty getting through security with insulin and syringes. They’re diabetic, yet not wearing a surgical mask. You aren’t worried about catching diabetes, but why? Diabetes is a life-threatening disease after all.
To answer this question, we need to examine the main difference between common illnesses.A disease is any abnormal condition that causes a disruption in the functions of a body tissue, organ, or entire organism. Diseases are recognized by a specific set of symptoms. Think about the diseases you know: a cold, the flu, measles, cancer, stroke, or diabetes, just to name a few. These diseases all disrupt the body in very characteristic ways. Now think about what causes these conditions: viruses, bacteria, fungi, smoking, genetic defects, etc.
There are countless diseases, each with its own unique and characteristic cause. But why can you ‘catch’ some diseases but not others? This is due to the two different types of disease: communicable and noncommunicable.
What Are Communicable Diseases?
Communicable diseases are spread from person to person or from animal to person. The spread or transfer can happen through the air, through contact with contaminated surfaces, or through direct contact with blood, feces, or other bodily fluids. A cold is an example of a communicable disease (a cold is the general term given to a viral infection of the upper respiratory tract).This is probably why those airline passengers mentioned at the start of this lesson were wearing masks. Viruses in the respiratory passageways can easily be coughed or even just breathed out.
So, if the inconsiderate cold-carrier sitting next to you on the plane coughs, viruses are spewed into your vicinity. You breathe, and suddenly those viruses have found a new respiratory tract to call home (yours!). That cold has now been passed from one infected person to another uninfected person, spreading the communicable disease.You can probably identify other communicable diseases.
If a disease is caused by viruses, bacteria, fungi, or protozoa it’s likely, although not always, communicable. Rabies, HIV, malaria, influenza, and athlete’s foot are just a few examples of communicable diseases you may be familiar with.
What Are Noncommunicable Diseases?
What about other things like cancer, heart disease, and diabetes? You can’t ‘catch’ these, right? These are examples of noncommunicable diseases, which are medical conditions that are not infectious and cannot be passed from one person or animal to another. Your fellow passenger with diabetes was either born with it or developed it later in life. Either way, you cannot ‘catch’ diabetes.Diabetes is one of the four most common noncommunicable diseases.
You’ve likely heard of the other three: heart disease, cancer, and chronic respiratory diseases (like asthma). It’s a good thing you can’t catch these diseases from others, because these four noncommunicable diseases kill roughly 30 million people per year worldwide.If you can’t catch these diseases, then how do you get them? Usually, you are either (1) born with the condition, (2) have a genetic predisposition (meaning you carry genes that make it more likely that you will develop the disease), or (3) something in your lifestyle increases your risk.
Things like diabetes and cardiovascular disease can develop as a result of obesity, poor diet, and physical inactivity. Cancers and respiratory diseases can be caused by tobacco use and exposure to pollution. Alcohol abuse can also lead to chronic health problems. The bottom line is, these conditions are not contagious, so there’s no need to wear a mask in the airport to protect your fellow travelers! No one is at risk because they are sitting next to you, unless you spend the 14-hour flight feeding them sugary gummy bears!
At some point in your life you will likely get a disease.
If you caught that disease from another person or animal, it is called a communicable disease. These illnesses are usually caused by viruses or bacteria and are passed through the air, through contact with contaminated surfaces, or through contact with bodily fluids. Examples include colds, the flu, or HIV.Noncommunicable diseases are conditions you were either born with, have genes for that increase your risk, or developed later in life as a result of your lifestyle. You can’t pass to or catch these diseases from others.
They include heart disease, cancer, diabetes, and chronic respiratory illnesses.
Communicable v. Noncommunicable Diseases
|*Illnesses caused by viruses or bacteria *Passed through the air, contact with contaminated surfaces, people, or bodily fluids *Examples: cold, flu, and measles||*Condition you are born with, have genes that increase your risk for, or develop later in life due to lifestyle *Not caught from other people and not contagious *Examples: cancer and diabetes|
When you are finished, you should be able to compare and contrast the characteristics of communicable and noncommunicable diseases.