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The immune system checklist

The immune system is your body’s set of defences against harmful bacteria and viruses it encounters. Now more than ever, we want to have strong immune systems to fight off any infections. But a healthy immune system relies on good habits, like a balanced diet and regular exercise, and is weakened by habits that harm your health. Have a look at the checklist below and ask yourself:

  • Do you frequently go through bouts of cold and/or flu?
  • Do you have any other diseases (e.g. diabetes)?
  • Do you have trouble with your weight?
  • Do you lead a stressful lifestyle?
  • Do you have irregular sleep patterns?
  • Do you smoke?
  • Do you drink alcohol excessively? 

If you answered yes to one (or several) of these questions, chances are that your immune health may be suboptimal. Let’s take a look at 6 potential signs of weakened immunity and what you might be able to do to help your body’s natural defences tackle infections.

  • Stress. You may notice that after a big project or a strong emotional experience you can sometimes become unwell. This happens because body secretes cortisol (a stress hormone) which affects the skin’s ability to keep out certain bacteria, viruses and fungi. Prolonged stress can affect the development of immune cells in your body, which can prevent them from being able to fight off infections1.
  • Frequent infections (cold and/or flu): Multiple bouts of cold/flu annually can be a sign of weakened immunity. When you get the flu, your immune system kicks into overdrive, heating up your body and causing a fever to fight off infection. Your throat hurts because the cells that line the airway produce inflammation to try stop the virus going further. If you go through multiple infections in a year, your immune system puts great strain on your body as it needs to produce antibodies at an accelerated rate.
  • Tiredness and fatigue: If you are feeling tired no matter how much sleep you get, it could be a sign of weakened immunity1. Poor sleep affects the skins regenerative abilities which might make healing wounds or fighting infections more difficult.
  • Drastic changes in bodyweight: If your weight is not healthy for your height (i.e. you are overweight/obese or underweight), you can have compromised immunity. When you are overweight2, increased fat cells can cause an increase in the immune cells secreting certain chemicals causing a chronic inflammation which may affect the body’s ability to absorb key nutrients. If you are underweight with nutritional deficiency, your immune system is almost certainly weakened, your bones may be more fragile and you may feel tired all the time4. Neither extreme is good for your immune health.
  • Wounds take longer to heal3: If you’ve noticed that minor injuries seem to be taking a long time to heal, your immune system might be weakened. The reason for this increased healing time might be chronic inflammation, or even age as our immune system weakens after early adulthood.
  • Tummy problems: If good and bad bacteria in your stomach become unbalanced, it can cause your immune system to go into overdrive. This in turn can lead to diarrhoea, constipation and gas. Often this is due to low levels of the “good” bacteria found in our digestive systems.

What you can do to combat weakened immunity

Even if you’ve noticed any of the above signs of weakened immunity, it’s not all doom and gloom. If you are wondering how to increase immunity, there are some simple steps you can take to help your weakened immune system4. Start forming good immune health habits now by following a few simple rules below!

  • To avoid infections, wash your hands regularly with soap and warm water, or using an alcohol-based gel. Avoid touching your eyes, nose and mouth with unwashed hands.
  • Eat a healthy, balanced diet containing lots of fresh fruit and vegetables. This will help provide your body with vitamins and minerals needed for healthy immune function. You can also take a vitamin and mineral supplement like Cal-C-Vita® that can help you restore healthy micronutrient levels in your body5.
  • Exercise regularly to reduce stress and improve circulation, both important factors for a healthy immune function.
  • Get quality sleep. Give yourself 8 hours of sleep every night and watch your immune system recover faster.
  • Reduce stress. If you find that regular exercise and a healthy sleep routine aren’t enough to reduce your stress levels, you can try relaxation methods like meditation or yoga.


  1. Andersen CJ, Murphy KE, Fernandez ML, Impact of Obesity and Metabolic Syndrome on Immunity, ADVANCES IN NUTRITION, Volume 7, Issue 1, January 2016, Pages 66–75,
  3. Ellis S, Lin EJ, Tartar D, Immunology of Wound Healing, Current Dermatology Reports 7(6), September 2018
  4. Morey JN, Boggero IA, Scott AB, Segerstrom SC, Current Directions in stress and Human Immune Function, Curr Opin Psychol. 2015 Oct 1; 5: 13–17.
  5. Natelson BH, Haghighi MH, Ponzio NM, Evidence for the Presence of Immune Dysfunction in Chronic Fatigue Syndrome, Clin Diagn Lab Immunol. 2002 Jul; 9(4): 747–752.
  6. How to prevent infections. Harvard Medical School, 2016. (Accessed 10/02/2020, at
  7. Gombart AF, Pierre A, Maggini S. A Review of Micronutrients and the Immune System-Working in Harmony to Reduce the Risk of Infection. Nutrients 2020;12.


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Your body is equipped with powerful natural defences and your immune system has many ways of dealing with threats from bacteria and viruses. The immune system is made up of three main defences mechanisms; physical barriers (skin and mucosa), cellular barriers (white blood cells) and antibodies. Nutrients such as vitamins and minerals are essential to the health and function of this complex network.

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You need to look after your immune system. Even though it may not feel like it, your immune system works 24 hours a day. Just as a plant needs water and sunlight, your immune system needs regular nourishment to support the body’s defence systems.

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Build your immunity

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