Common seasonal bugs

Dr Luke Powles
Associate Clinical Director, Health Clinics Bupa Global and UK
03 May 2023
Next review due May 2026

Some illnesses happen more often at different times of the year. Knowing what these common seasonal bugs are can help you to prepare, and treat them if you get unwell. Here, I explain what seasonal illnesses are, and what you can do to manage them at home.

person spraying hand sanitiser on a child's hand

What are seasonal bugs?

Seasonal bugs are illnesses which are more likely to happen at certain times of the year. For example, flu tends to be more common between December and March.

That doesn’t mean you can’t get ill with it outside of these months. But, usually, people tend to get flu, and these kind of illnesses, during winter.

And it’s not just respiratory illnesses which increase during the winter. You can also be more likely to get norovirus – the winter vomiting illness too.

How do I know if I have a seasonal illness?

If you start to sniff and sneeze in May – it could be a seasonal allergy such as hay fever. This is because it’s less likely you will have colds and flu during warmer months. But, if you feel run down and start to have a sore throat in late autumn and winter, then it’s more likely you could have a common seasonal illness.

Below I discuss the symptoms of common seasonal bugs – but always see a doctor if you’re concerned about your health.

What causes seasonal illnesses?

Seasonal illnesses can happen for a number of reasons. Firstly, during the colder months people tend to gather inside more. This can make it easier for bugs to pass from one person to another.

Most seasonal illnesses are passed on through coughs, sneezes, or droplets of saliva. Bugs can also be passed on through touching contaminated surfaces. This is why maintaining good hygiene and avoiding those who appear unwell can help to reduce your risk of seasonal illness.

Seasonal illnesses may also be linked to a reduction in temperature during cooler months. This is because some viruses thrive better at lower temperatures. Similarly, if you go out when it’s cold your nasal immunity (one of the first lines of defence for respiratory infections) can be reduced. This can make it more likely you’ll pick up coughs and colds.

And finally, people tend to have lower Vitamin D stores during winter. Vitamin D is involved in immunity, and so this can increase your chances of infection in the winter. You should supplement with Vitamin D between October and March in the UK.

What are some common seasonal bugs?

There are some common viruses which are more likely during the winter. Here we explain what they are, and what the symptoms look like.


Flu tends to come on suddenly. It’s caused by the influenza virus. It can cause a fever and body aches. It can also cause sore throats, headaches, nausea, or lack of appetite. Fatigue, coughs, and chills are also possible signs of flu. Generally, with flu you feel unable to carry out your regular daily tasks and need to rest more.


A range of viruses can cause the common cold, including rhinoviruses and adenoviruses. Usually the symptoms include sneezing, sore throats, mild headaches, and a runny nose. It’s possible to get a fever with a cold, but most people don’t. You can also feel more tired than usual. A cold usually resolves within one to two weeks.


This unpleasant but short-lived stomach virus leads to vomiting, nausea, diarrhoea, and stomach cramps. Some people may also experience body aches, fevers, and chills. This virus tends to come on fairly quickly after you have been exposed to the infected particles.


Covid-19 is caused by the SARS-coV-2 virus. It causes symptoms such as fever and chills, body aches and headaches. It can also cause loss of taste or smell. A sore throat usually develops into a cough. Whilst covid is mild and self resolves in many people – for some symptoms can progress and affect the lungs.

How can I treat seasonal bugs at home?

The treatment for many common seasonal bugs is similar. If you have a simple cold, then it’s a good idea to stay hydrated and rest if you feel tired. You can also use lemon and honey drinks to soothe a sore throat. Some people find inhaling eucalyptus oil (diluted in steam) helps with nasal congestion and making warm soups with garlic or ginger may have some anti-viral effects.

When it comes to systemic (all over) body infections such as flu or COVID it becomes more important for you to prioritise rest. This allows your body a chance to repair and fight off the infection better. You can also use paracetamol for aches or pains, and to help to reduce a fever.

For coughs, honey mixed with lemon is thought to be just as effective as cough medicines in reducing symptoms. If you get flu or COVID and have heart disease, a lung condition, experience a very high fever or breathing difficulties, see a doctor immediately.

For norovirus, the advice is usually to try and stay hydrated by sipping water, possibly with some added electrolytes. Eating plain food like dry toast can also help. But if you’re becoming very dehydrated, or if your symptoms aren’t improving after a couple of days then seek medical assistance.

We understand it's important to get back to feeling yourself again as quickly as possible. That's why with our health insurance you can get fast access to the treatment and support you need, when you need it. Learn more with our useful guide to understanding health insurance.

Dr Luke Powles
Dr Luke Powles
Associate Clinical Director, Health Clinics Bupa Global and UK



Julia Ebbens, Health Content Editor at Bupa UK

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