Krankheit
In short
A disease or illness is a condition that stops the body or mind from working normally. It is often caused by germs, genetics, or lifestyle factors.
In plain words
It is when you feel unwell because something is wrong inside your body. This can be a temporary bug like a cold or a long-term problem like diabetes.
A simple example
A person catches a virus from a sneeze, which leads to a fever and a cough. This temporary state is a sickness.
Why it matters
Understanding diseases helps doctors create medicines and vaccines. It also helps people make better choices to stay healthy.
Easy to mix up
Do not confuse a disease with a symptom; a fever is a symptom, while the flu is the disease.