Body aches are among the most common symptoms of the flu alongside a fever. But why does this happen, and can a person have flu body aches but no fever?
What causes body aches when you have the flu?
Before we get to why the flu causes body aches, we first need to understand what the flu is. The flu, or influenza, is a viral infection that attacks the respiratory system.
Different strains or types of flu can infect people. Which is why yearly flu vaccines are important to help prevent people from getting sick.
Flu strains also vary in severity, with some strains causing more serious symptoms or even death, while other strains cause the normal symptoms associated with the flu — fever, coughs and colds, and body aches and pains.
But what exactly does the flu do to have these effects on our body?
The coughs and colds are pretty self-explanatory; since influenza is a virus that affects the respiratory system, coughs and colds are a common and even expected symptom.
On the other hand, the aches and pains are not exactly symptoms caused by the virus itself, but by how the body responds to illness.
Whenever you get an infection, such as the flu, your immune system does its best to fight it off. Your immune system sends out white blood cells that produce chemicals. These chemicals are called cytokines and interleukins which help kill off any infectious diseases.
However, these chemicals also have the effect of causing muscle aches and pains. This is the main reason why whenever you have the flu, or any other illness, muscle aches and pains are a common symptom.
Why do you get a fever when you have the flu?
Aside from muscle aches and pains, another common symptom is a fever.
And just like aches and pains, a fever is not directly caused by the virus infecting your body. It is a part of the immune response that your body has. Which helps drive away and kill off any foreign invaders.
What happens during a fever is that your body sends out signals to increase your body temperature. This can help kill off any infection that you might have, since certain types of viruses and bacteria die off in high temperatures.
However, a fever can also have the unintended effect of making you feel much worse. And coupled with the symptoms of influenza such as muscle aches, coughs, and colds, getting sick can really make you feel terrible.