Why Do We Keep Getting Ill? A Practical Guide

A new infection or symptoms that never fully clear?

When a runny nose and cough keep returning, it can feel as though you are ill all the time. Start by considering whether you recover between episodes or whether the same problem has continued for longer.

Many different viruses cause colds. Recovering from one does not protect you against all the others. More contact with people at home, work or in childcare settings can mean more opportunities to catch an infection. [1]

What can look like repeated colds

Similar symptoms do not always have the same cause. A cough can also occur with asthma, where symptoms may vary over time, appear at night or follow exposure to a trigger. [5] A runny nose accompanied by sneezing or itchy eyes can be related to allergies. [6]

These patterns can help guide an assessment, but they do not establish a diagnosis on their own. Mention whether symptoms relate to a particular place, season, physical activity or contact with animals.

What to record before seeing your doctor

A brief record can be more useful than remembering that you have been ill “many times”. Use your phone or a notebook. You do not need to create your own health score.

Bring a list of medicines and supplements you take regularly. For a child, information about growth, food intake and previous hospital admissions is also useful.

When to see a doctor

Arrange an assessment if illnesses repeatedly become severe, recovery is unusually slow or symptoms persist. The pattern of illness and your overall health matter more than the number of colds alone.

• Repeated pneumonia or other serious bacterial infections.
• Unusual infections, repeated hospital admissions or a need for intravenous antibiotics.
• Unexplained weight loss; in a child, poor weight gain or slowed growth.
• A poor response to prescribed treatment or a family history of serious recurrent infections.

The pattern of recurrent infections can warrant specialist assessment. [4]

If you have a higher risk of serious illness, for example because you take medicines that suppress the immune system, seek advice promptly about new symptoms and follow your clinician’s instructions. [2]

How decisions about tests are made

Your doctor considers your history, examination and previous illnesses. Depending on the findings, they may recommend targeted tests or refer you to an allergist, immunologist or another specialist.

Not every recurring cough needs the same set of tests. A commercial microbiome test or a measurement of one nutrient cannot fully explain why you keep getting ill.

Practical prevention at home and work

Focus on situations in which infections can spread. You can include the following measures in everyday life:

• Ventilation: bring fresh air into rooms you share with other people.
• Hand hygiene: wash your hands and cover coughs and sneezes with a tissue or your elbow.
• Consideration when ill: reduce close contact with others, especially people at higher risk.
• Vaccination: ask your clinician about recommendations for your age, health and local circumstances.
• Additional protection: in higher-risk situations, a well-fitting respirator and avoiding crowded indoor spaces can help.

These measures reflect guidance on preventing respiratory illnesses. [2]

For the wider connections between sleep, nutrition and immune function, see our guide to immunity and vitality. Here, the focus is on reducing opportunities for another infection.

Recovery and returning to your routine

While you are ill, allow for tiredness, drink enough fluids and follow the recommended treatment. Plan your return to work or exercise according to the course of the illness and how you feel.

Antibiotics do not work against the viruses that cause common colds. Whether you need them depends on the diagnosis. Do not use antibiotics left over from an earlier illness or medicines prescribed for someone else. [3]

Contact your doctor if you become worse again after improving, a fever returns or new symptoms develop. Returning to your full workload may take longer if you are still struggling with everyday activities.

What you can do now

1. Build a record of each episode. Add dates, symptoms and the results of previous assessments.
2. Choose one practical change to your surroundings. For example, improve ventilation at work or reduce contact with people who are ill.
3. Consider whether you need an assessment. Severe, persistent or worsening symptoms need more than a change of routine.
4. Review the supplements you already take. Bring the list to your appointment. Do not combine products simply because each label mentions immunity.

For help understanding supplement ingredients and formats, visit our Immunity Advisor. Explore the gut environment further in our article on digestion and gut health.

Common questions about recurring infections

How many colds suggest an immune disorder?

The number alone is not enough. Age, exposure to infections, severity, complications and recovery between episodes all matter. A clinician can assess the overall pattern.

Can I still get ill if I take vitamins?

Yes. Supplements do not guarantee protection from infection. The reason for taking one should reflect your individual needs.

Is every recurring runny nose an infection?

No. Persistent or recurring symptoms can have another cause, such as an allergy. A clear description of symptoms and an assessment when needed can help identify the cause.

Sources and further reading

1. CDC: the common cold and its causes
2. CDC: preventing respiratory illnesses
3. NHS: respiratory tract infections
4. AAAAI: recurrent infections and immunodeficiency
5. NHS: asthma, symptoms and treatment
6. NHS: allergic rhinitis

This educational article does not replace an individual medical assessment. English version prepared on 19 September 2026.