What Are The Signs Of A Weak Immune System?

Written by Angie Arriesgado
featured image for blog post on weak immune system

Germs, viruses, and other harmful microbes are everywhere. We don’t see them, but they’re there anyway. Fortunately, a healthy immune system can fight off most of these unseen enemies. But what about those whose natural defenses are easily overpowered by pathogens? In this blog post, we’ll talk about the common signs of a weak immune system and what we can do to boost it.

Here’s how our immune system protects us…

Think of our immune system as our body’s 24/7 defense system. It’s our personal army comprised of cells, tissues, and organs that work together around the clock to eliminate threats to our health.

These threats include viruses, bacteria, germs, fungi, and toxins. Anything that the body doesn’t recognize as its own and can potentially harm you is marked as a threat and eliminated by our immune system.

There are two types of immune response (1):

Innate (general) immunity

This is the body’s primary and non-specific immune defense. When pathogens enter the body, our innate immunity swiftly gets to work and fights them off. A person with robust immunity may not notice anything different, but someone with poor immunity may fall ill when fighting an ongoing infection. Macrophages and neutrophils form part of our innate immune response.

Adaptive (specific) immunity

Our immune system remembers the pathogens it had previously eliminated. When we encounter that particular pathogen again, the immune system remembers how it responded in the past. This shortens the infection period or prevents it altogether. Antibodies, T-cells, and B-cells form part of our adaptive immunity. Successful vaccinations also rely on our adaptive immune response.

That said, immune response varies widely from one person to another. This is why some people get sick quickly while others remain unaffected. It is therefore important to ensure optimal immune health.

The 6 common signs of a weak immune system

A weak immune system can make you more prone to infections and severe symptoms. Here are the most common signs of weak immunity:

1. You catch a cold easily              

The common cold is truly elusive. It mutates so frequently that adaptive immunity doesn’t work against it, and scientists have not been able to develop a vaccine for it. Unfortunately, no one’s exempt from catching it. In fact, most of us catch it once or twice a year. The good thing is symptoms usually resolve in about a week.

However, if you catch the common cold multiple times a year and symptoms last longer than 7-10 days, then this may be a sign of a weakened immune system.

2. You get sick often

In addition to catching the common cold more often than normal, someone with a weak immune system will be more susceptible to various infections. According to the AAAAI, the following may be signs of a weak immune system:

  • You need more than 2 courses of antibiotics in one year
  • Recurring pneumonia
  • More than 4 ear infections in one year
  • Suffering from chronic sinusitis

3. Frequent stomach issues

No single organ that serves as “headquarters” for the immune system, but a great majority of immune cells do reside in the gut (2). It’s therefore not surprising that a person with weak immunity will be prone to gut issues, such as gas, bloating, diarrhea, and constipation.

While eating probiotics-rich food and/or taking probiotics supplements can help improve gut health, it’s best to get checked by a doctor if symptoms last for several days or weeks.

4. Slow-healing wounds

Even a non-clumsy individual can get into accidents from time to time. A scrape on the knee, a small cut on the finger, a scratch from a pet, etc. Most minor wounds only take a few days to heal, so it’s no big deal for many people.

However, someone with a weak immune system may find their wound taking a longer time to heal. Depending on the location and severity, the wound may even be prone to infection no matter how well you clean and protect it.

5. Autoimmune diseases

Autoimmune conditions occur when the body’s immune system mistakenly attacks healthy cells and tissue. Think of it as a malfunction. Unfortunately, there’s no clear reason why the body does this.

There are more than 100 autoimmune diseases affecting millions of people worldwide. Examples are lupus, type 1 diabetes, psoriasis, Crohn’s disease, Celiac disease, and more. Symptoms range from mild to life-threatening. There are also more women affected by various autoimmune disorders than men (3).

6. Extreme fatigue

It’s normal to feel tired all the time, especially when busy with work, school, and life in general. But if the fatigue doesn’t go away even after a night of restful sleep, then something may be up with your immune system.

Try eliminating possible reasons first, e.g. reduce workload, take more breaks, exercise to get a dopamine boost, resolve problems at home, etc. If none of them work and you’re still exhausted no matter what you do, it may be a sign of a weak immune system.

Can immune support vitamins help strengthen immunity?

The short answer is yes. Immune support vitamins from food and supplements can help boost immunity. Nutrients contribute to immune cell metabolism and function. But balance is important, too. For instance, overnutrition is linked to chronic inflammation, while undernutrition may lead to poor immune health (4).

An immune support vitamin that may help is vitamin C. It’s a potent antioxidant that helps protect against free radical damage. It can also shorten the duration of a respiratory tract infection (5). However, don’t just take ordinary ascorbic acid pills. A Liposomal Vitamin C formulation is a much better option for optimal absorption rates.

Also, taking a multivitamin is an excellent idea. We have formulated both our Adult and Women’s Multivitamins with 25 essential nutrients to help fill any gaps in your diet. 

For a comprehensive list of supplements that can help improve your immunity, check out this blog post on the 12 best supplements that can help boost your immune system.


It’s easy to take our immune system for granted, especially when we’re healthy and go for long stretches without getting sick. By recognizing the signs of a weak immune system, you can take proactive measures to keep your immune system in tip-top shape; these include taking immune support vitamins like Vitamin C and multivitamins.


(1) InformedHealth.org [Internet]. Cologne, Germany: Institute for Quality and Efficiency in Health Care (IQWiG); 2006-. The innate and adaptive immune systems.

(2) Wiertsema SP, van Bergenhenegouwen J, Garssen J, Knippels LMJ. The Interplay between the Gut Microbiome and the Immune System in the Context of Infectious Diseases throughout Life and the Role of Nutrition in Optimizing Treatment Strategies. Nutrients. 2021;13(3):886. Published 2021 Mar 9.

(3) Autoimmune Diseases, https://my.clevelandclinic.org/health/diseases/21624-autoimmune-diseases

(4) Changes in Nutritional Status Impact Immune Cell Metabolism and Function, Yazan Alwarawrah, Kaitlin Kiernan, Nancie J. MacIver, Front. Immunol., 16 May 2018 Sec. Immunological Tolerance and Regulation Volume 9 – 2018

(5) Vorilhon, Philippe et al. “Efficacy of vitamin C for the prevention and treatment of upper respiratory tract infection. A meta-analysis in children.” European Journal of Clinical Pharmacology 75 (2018): 303-311.