Back in the day, folks thought sickness was a punishment from the gods or caused by evil spirits.

Hippocrates and Galen later came along with the idea of humorism, saying that too much or too little blood, phlegm, black bile, or yellow bile in our bodies made us sick.

Later, a Renaissance doctor named Paracelsus suggested that sickness comes from outside stuff, not just what's inside us.

What do we know now?

Today, we know diseases are either infectious or non-infectious.

Infectious diseases are from germs like bacteria and viruses. They sneak into our bodies through the air, food, drinks, or even a tiny cut.

Take a common cold, for instance. If someone with a cold coughs on their hand and then touches a doorknob, they leave germs there. The next person who touches that knob might pick up the cold virus, especially if they then eat without washing their hands.

Non-infectious diseases, though, aren't spread by germs. They come from things like our environment, lifestyle choices, and genes. For example, sunburn happens from too much sun without sunscreen, and heart disease can come from not moving enough, eating unhealthy, or just from family history.†

We can't change our genes, but we can surely dodge non-infectious diseases by eating better, staying active, and avoiding bad stuff like smoking.†

Not every germ that enters our body makes us sick, thanks to our awesome immune system. It's a team of cells, tissues, and organs fighting off invaders like bacteria and viruses. It also finds and fixes faulty cells. A strong immune system is key to staying healthy.†

But germs can be sneaky and change quickly, sometimes faster than our immune system can keep up. They can hide inside our own cells or be tough for those with weaker immune systems to fight off.

Washing hands is super simple but super important, especially during flu season.

Dirty hands can carry cold viruses and other germs that get into our bodies when we touch our face.

So, always wash your hands after you've been out and about or touched something iffy.

Too much stress is bad news for our health. It makes hormones that can weaken our immune system, leaving us open to getting sick. †

Understanding how stress messes with us and managing it through chill-out exercises, moving our bodies, and getting enough sleep is super important.

Good sleep is crucial for a fighting-fit immune system.

Not sleeping enough makes it harder for our bodies to battle infections, so we get sick more often.

Sticking to a sleep schedule and creating a comfy sleep environment (like less screen time before bed) helps big time.

Oral health might not seem like a big deal, but it is.

Bad oral health can let nasty bacteria into our bloodstream, making us sick in other ways.

Brushing, flossing, and regular dental visits keep our mouths healthy and our immune systems happy.†

A balanced diet is the foundation of immune health.

Eating fruits and veggies for vitamin C and fatty fish for vitamin D is vital.

Eating well, with less alcohol, and drinking plenty of water helps our bodies use nutrients and get rid of toxins.†

Sometimes, immune systems can go bonkers.

Autoimmune diseases make the immune system attack our own cells, and immunodeficiency disorders mean our immune system is too weak.

Both can make us more prone to infections and other health issues.

Managing these requires a doctor's help and lifestyle changes to boost our immune system and overall health.