Your immune system works tirelessly to protect your body from harmful invaders.

However, did you know factors beyond diet and exercise can impact how it functions? Here are five surprising things that can influence your immune system in positive and negative ways.

1. Stress: How It Weakenes Your Defenses

While stress is a natural part of life, chronic stress can weaken your immune system over time by releasing cortisol. This hormone interferes with lymphocyte production, which means that during stress, you have fewer white blood cells circulating and are more vulnerable to infections. Meditation, mindfulness and exercise could help you reduce anxiety, which will strengthen your immune system.

2. Laughter: The Unexpected Immunity Booster

It might sound too good to be true, but laughter can strengthen your immune system by decreasing stress hormones and increasing immune cells and infection-fighting antibodies. This helps improve your disease resistance.

 Laughing also helps your mental health, making it easier to go through difficult situations like loss or disappointments. The stress-busting power — which can relax your muscles for as much as 45 minutes — and immune-cell boost are a one-two punch for improving your immunity.

3. Sleep: Key to a Strong Immune System

Getting seven to nine hours of good sleep can play a significant role in maintaining a strong immune system. During deep sleep, your body produces cytokines — proteins that help fight infections and inflammation.

 Without enough rest, your immune response weakens, making you more susceptible to illness. If you have insomnia or sleep apnea, consider speaking with a doctor to improve your rest and immune health.

4. Germs: Why Your Immune System Needs Them

Yes, you read that right. It may sound counterintuitive, but not all gems are bad. Your immune system learns when exposed to new bacteria and viruses. When it encounters one, it remembers it, helping the body respond faster if it happens again.

It's about balance — enough exposure to build immunity but not too much. However, weak circulation can hinder this process. Poor blood flow can reduce the efficiency of your immune response, as your body struggles to transport vital cells and has a hard time fighting off infections and healing wounds. Getting enough germ exposure to support a resilient immune system makes maintaining good circulatory health even more important.

5. Cold Temperatures: The Chill That Strengthens Your Defences

People may associate chilly weather with getting sick, but brief exposure to cold temperatures can actually boost your immune system. Taking a cold shower stimulates white blood cell production, helping your body fight infections.

Everyday Changes for a Healthier Immune System

Taking care of your immune system goes beyond eating the right foods or exercising on a daily basis. Other habits have a profound effect on how well your body defends itself. You can strengthen your immune system and improve your health by prioritizing a better sleep schedule, managing stress, enjoying moments of laughter, engaging in cold exposure safely, and improving your circulation.