The immune system is a host defense system comprising many biological structures and processes within an organism that protects against disease. Even simple unicellular organisms such as bacteria possess a rudimentary immune system in the form of enzymes that protect against bacteriophage infections.

There are 6 signs you have weakened immune system:

1. Your Stress Level is Sky-High

It’s not a coincidence that you tend to get sick after a big project at work or following an emotional situation at home.

According to a report by the American Psychological Association, long-term stress weakens the responses of your immune system.

“That’s because stress decreases the body’s lymphocytes, the white blood cells that help fight off infection. The lower your lymphocyte levels, the more you’re at risk for viruses like the common cold,” explains Nadia Hasan, DO, a physician at Delancey Internal Medicine.

2. You Always Have a Cold

It’s perfectly normal for adults to sneeze and sniffle through two or three colds each year. Most people bounce back in seven to 10 days.

“During that time, it takes the immune system three to four days to develop antibodies and fight off pesky germs,” says Dr. Hasan.

But if you’re constantly catching colds – or have a cold that’s won’t run its course – that’s a clear sign your immune system is struggling to keep up.

3. You Have Lots of Tummy Troubles

If you have frequent diarrhea, gas or constipation, it could be a sign that your immune system is compromised.

Research shows that nearly 70 percent of your immune system is located in your digestive tract. The beneficial bacteria and microorganisms that live there defend your gut from infection and support the immune system.

Low amounts of these helpful gut bacteria can leave you at risk to viruses, chronic inflammation and even autoimmune disorders.

4. Your Wounds Are Slow to Heal

Your skin goes into damage control mode after you get a burn, cut or scrape. Your body works to protect the wound by sending nutrient-rich blood to the injury to help regenerate new skin.

This healing process depends on healthy immune cells. But if your immune system is sluggish, your skin can’t regenerate. Instead, your wounds linger and have a hard time healing.

5. You Have Frequent Infections

If you seem battle frequent infections, your immune system might be sending you red flags.

The American Academy of Allergy Asthma & Immunology reports that signs of a possible immune deficiency in adults include:

• Having more than four ear infections in one year
• Developing pneumonia twice during a one-year period
• Suffering from chronic sinusitis or more than three episodes of bacterial sinusitis in a year
• Needing more than two courses of antibiotics a year

6. You Feel Tired All the Time

You know that burning the candle at both ends is bound to leave you feeling sluggish. But if you’re getting enough sleep and still suffering from exhaustion, it’s worth considering if your immune system is trying to tell you something.

When your immune system struggles, so does your energy level.

“That’s because your body is trying to conserve energy to fuel your immune system so it can fight off germs,” explains Dr. Hasan.