Diseases are any condition that interferes with the proper
functioning of the body and mind. There are two main
types of diseases. Noncommunicable
Diseases that are NOT
Communicable spread, but usually caused
by a combination of :
Diseases that are spread, or passed
from one person to the next 1. conditions they were born
Also called infectious 2. how people live
diseases 3. environmental factors.
Examples include: These diseases are often
called chronic because
they last for along period
Common cold, flu, HIV of time.
Heart diseases, cancer, and
Communicable diseases are caused by germs or pathogens. These
are microorganisms that cause disease. Microorganisms are
organisms that are too small to be seen. They can only be seen
with a microscope!
Examples of pathogens include:
• Tiny one-celled organisms that live on most surfaces.
•Most common life form on earth
•Can live in water, soil or a person’s body
•Not all bacteria cause disease (of 1,600 types, fewer than 200 cause
illness) Some bacteria can even be helpful!
Diseases Caused by Bacteria:
Bacterial pneumonia, pinkeye, strep throat, most foodborne illnesses (e-
coli and salmonella), tetanus lock jaw, Lyme disease, syphilis
•Smallest and simplest life form (they are actually submicroscopic!)
•Must have a “host” to survive. Viruses can only live, grow and
reproduce inside another living cell
•There is no cure for viral infections, but their symptoms can be
treated by medicines that help to relieve the symptoms.
Diseases Caused by Viruses:
Common cold, influenza (seasonal and H1N1),mononucleosis,
hepatitis, HIV, chicken pox, herpes
Did you know? Viruses are far smaller than bacteria. Viruses
look like balls with spikes sticking out, some others look like
loaves of bread or tadpoles and others look like metal screws
with spider legs
•Microscopic one-celled organisms
•Commonly found in fresh water, oceans, streams and soil
•Only a few types cause illness in humans
•Spread through contaminated water, food, or dirty hands
Diseases caused by Protozoa:
•Amoebic dysentery (Amoebic dysentery is an infection of the intestine which
can cause diarrhea and severe upset stomach)
•Malaria (spread by a mosquito that injects the protozoa into the
•Fungi are a group of about 100,000 species of simple plants that cannot make
their own food (they do not contain cholorophyll), so they draw nutrition from
nearby plants and animals, living or dead. They also can live in damp dark places
since they do not use light to make food.
•Examples include mushrooms and yeasts.
Good fungus or bad? There are many varieties of mushrooms that people
like to eat, and we also use yeasts to make beer and bread! Fungus are also
important recyclers- they turn our trash into soil! Bad fungus are really just good
fungus trying to do their job too early!.
Diseases caused by fungi include:
•Ringworm – yes, there is no worm involved!
•Many allergies (fungus irritates the nose, cause watery eyes and breathing
•People with weakened immune systems by cancer or AIDS or taking certain
Worms that live in or upon another living organism
Diseases caused by parasitic worms:
•Pinworm (intestinal infection caused by tiny
•Trichinosis (trichinella worm from raw or
undercooked meat, pork and sausage causes
intestinal upset, diarrhea)
Other parasitic worms include
round worm, hookworm, whip
worm and tapeworm!