Why Is My Immune System Weak and How Can I Strengthen It?

A strong immune system is your body's defense against germs and infections. But when it's not functioning properly, you become more susceptible to illnesses. Read on to understand why your immunity may be low and science-backed ways to naturally boost it.

Your immune system works hard 24/7 to protect you. It's a complex network of cells, tissues and organs that bands together to defend your body against bacteria, viruses, toxins and more.

When foreign invaders enter your body, your immune system springs into action. It releases antibodies and white blood cells to destroy these threats before they can make you sick. Pretty impressive, right?

But what happens when your immune system is weakened and can't properly protect you?

You may catch frequent colds, the flu and other bugs going around. Even small infections can linger longer and become serious.

Below we'll explore the major lifestyle factors that can run down your immunity. Then we'll discuss evidence-based ways you can strengthen your body's defenses naturally.

Let's start by understanding why your immune system might be weak in the first place.

What Causes a Weakened Immune System?

Many aspects of modern life can chip away at your immune defenses over time. The main culprits include:

Chronic Stress

Ongoing stress causes your body to produce higher levels of the hormone cortisol. Over time, chronic cortisol spikes inhibit the function of immune cells that fight infection.

One study found that people caring for spouses with dementia took 40% longer to recover from wounds. Their immune systems were compromised due to chronic stress.

Poor Diet

Your immune cells need proper nutrition to function efficiently. But the typical Western diet of processed foods provides few vitamins, minerals and antioxidants.

Diets high in sugar, saturated fats and sodium promote inflammation. This can impair immune cells and increase your infection risk.

One study found that zinc deficiency from poor nutrition alone caused about 1.4% of deaths worldwide. Zinc supports several immune cell types.

Lack of Sleep

Your body needs adequate rest to regenerate immune cells. But many adults don't get the recommended 7-9 hours per night.

One study showed that those sleeping less than 5 hours were 4.2 times more likely to catch a cold compared to those sleeping over 7 hours.

Smoking and Heavy Alcohol Use

Smoking one cigarette suppresses immune cells in your bloodstream for up to 2 hours. Chronic smoking also damages lung tissue, making you more prone to respiratory infections.

Drinking excessive amounts of alcohol can damage immune cells in both the blood and organs like the lungs.

Certain Medications

Medications that suppress immunity are often given after organ transplants to prevent rejection. Chemotherapy also impairs immune function.

While necessary, these drugs reduce the ability to fight infections. Speak with your doctor about infection prevention while on immunosuppressants.

Autoimmune Disorders

Autoimmune diseases like rheumatoid arthritis occur when the immune system mistakenly attacks your own body's tissues. This can raise susceptibility to infections.

Age-Related Decline

As you get older, your thymus gland shrinks and produces fewer immune cells called T cells. Chronic diseases also become more common with age, raising infection risk.

Now that you know why your immunity might be low, let's talk about ways to improve it.

14 Lifestyle Changes to Boost Your Immune System

Supporting your immune system naturally is possible with a few evidence-backed habits:

1. Eat More Fruits and Vegetables

Fruits and veggies provide vitamins A, C, E along with antioxidants that enhance immune cell function.

One daily serving of fruits and veggies lowers infection risk by up to 33% compared to none per day. Shoot for 5-9 servings per day.

2. Choose Lean Proteins

Protein supports the production of antibodies and immune cells. Choose lean options like poultry, seafood, eggs, legumes, nuts and seeds.

3. Eat Prebiotic and Probiotic Foods

Prebiotics and probiotics improve the balance of gut bacteria. Yogurt, kimchi, miso, kefir and fermented foods are great sources.

4. Stay Hydrated

Water flushes toxins, prevents constipation and thins mucus so your body can clear viruses and bacteria faster.

Drink at least 64 ounces (8 cups) of water per day. Carry a bottle and sip often.

5. Take a Zinc Supplement

Zinc supports several types of T cells. The RDA is 8-11 mg per day for adults. Foods like oysters, meat and seeds provide zinc.

6. Consider a Vitamin D Supplement

Low vitamin D levels correlate with a higher susceptibility to infection. Try to get 600-800 IU per day.

7. Wind Down and De-Stress

Chronic stress impairs immune function. Carve out time to unwind through yoga, meditation, massage and other relaxing activities.

8. Get Enough Quality Sleep

Aim for 7-9 hours per night. Avoid screen time before bed and create a restful sleep environment.

9. Exercise Regularly But Not Too Much

Occasional intense and prolonged exercise can temporarily suppress immunity. Aim for 150 minutes per week of moderate activity like brisk walking. Spread exercise sessions throughout the week for best immune support.

10. Have Good Hygiene Habits

Wash your hands often, especially before eating. Avoid touching your eyes, nose and mouth to prevent germ transmission. Disinfect surfaces and shared items.

11. Stop Smoking and Limit Alcohol

Smoking just 1 cigarette suppresses immune cells. Heavy alcohol use also impairs immunity. If you smoke or drink excessively, look into support services to help change these habits.

12. Maintain a Healthy Weight

Obesity and being underweight are linked to poorer immune function. Eat a balanced diet and stay active to keep a normal BMI.

13. Get Regular Medical Care

See your doctor for recommended health screenings and vaccinations like the flu shot. Stay current on these even when you feel healthy.

14. Look Into Immune-Boosting Supplements

Some supplements like vitamin C, zinc, elderberry and medicinal mushrooms have science backing their immune-enhancing claims. Discuss options with your doctor.

Making even a few of these changes can strengthen your body's defenses and prevent illness. But don't try to overhaul everything at once.

Pick 2-3 healthier habits to focus on, then add more when those stick. For instance, start going to bed an hour earlier and taking a daily walk. After those become routine, drink more water and add garlic to your meals.

Small steps done consistently will benefit your immune function more than a major lifestyle overhaul done sporadically.

When to See a Doctor About a Weak Immune System

A healthy immune system can bounce back after a brief challenge like a cold virus. But when infections are frequent or severe, it may be time to see a doctor.

Signs your immune function needs medical attention include:

  • Catching more than 2-3 colds per year
  • Infections that last longer than 2 weeks or keep recurring
  • Very slow wound healing
  • An immune disorder diagnosis like HIV or lupus
  • Taking immunosuppressant drugs

Your doctor can help identify any vitamin and mineral deficiencies through blood work. For example, over 30% of people are low in vitamin D which can raise infection risk.

Immune function testing is also available to measure T cell counts and activity. Based on your results, your doctor may suggest immune-boosting supplements.

For those with autoimmune disorders, medications that calm the overactive immune response may be prescribed. Your doctor can also provide guidance on protecting yourself against infection.

In some cases, referral to an immunologist who specializes in immune disorders may be needed for additional testing and treatment.

The Bottom Line

Your first line of defense against germs is a healthy immune system. While immunity naturally declines with age, you can take charge by making lifestyle changes.

Eat more fruits, vegetables and lean proteins. Stay active but don't overdo it. Get enough sleep and manage stress. Hydrate well and avoid smoking.

Making smart, consistent choices will go a long way in supporting your body's ability to fight infection and stay well. But don't hesitate to see a doctor if issues persist.

With a little self-care and guidance from your healthcare provider, you can keep your immune system strong well into your later years.