The Most Common Health Problems During Summer and How to Stay Well
By Dr Daniel Gordon • 27, Jun 2026
Summer is often seen as one of the healthiest times of the year. Colds and flu become less common, the days are longer and people spend more time outdoors.
In reality, summer brings a different set of health problems. Every year, I see patients with severe hay fever, worsening asthma, dehydration, heat exhaustion, flare-ups of long-term health conditions and food poisoning.
While summer once brought a quieter period for many GP practices, that is no longer the case. Heatwaves, an ageing population and increasing pressure across the healthcare system mean summer can now be just as busy as winter.
Here are the health problems I see most often during the summer months.
Severe hay fever and worsening asthma
Hay fever is far more than a few sneezes.
For many people it causes blocked noses, streaming eyes, headaches, poor sleep and constant fatigue. When high pollen levels combine with air pollution, asthma symptoms can also become much worse.
Common symptoms include:
Sneezing
Itchy or watery eyes
Blocked nose
Headaches
Wheezing
Chest tightness
Shortness of breath
If you have asthma, needing your reliever inhaler more often than usual is a sign that your asthma may not be well controlled.
Starting treatment early, checking the pollen forecast and avoiding unnecessary exposure on high pollen days can make a significant difference.
To learn more about managing asthma during the summer, read Asthma in Summer: Why Heat, Pollen and Pollution Can Make Symptoms Worse.
Heat exhaustion and dehydration
Heat-related illness is becoming increasingly common during hotter summers.
Many people do not realise they are dehydrated until symptoms have already developed.
Early signs include:
Thirst
Headache
Dizziness
Dark urine
Feeling unusually tired
Muscle cramps
If dehydration continues, it can lead to heat exhaustion.
Symptoms of heat exhaustion include:
Heavy sweating
Weakness
Nausea
Fast heartbeat
Confusion
Feeling faint
Most people recover quickly by moving somewhere cool, drinking fluids and resting.
However, if someone becomes confused, collapses or remains unwell after cooling down, heatstroke must be considered and emergency medical help should be sought.
Older adults, young children and people with long-term medical conditions are particularly vulnerable during heatwaves.
For practical guidance on recognising and preventing heat-related illness in older people, read Heat and Dehydration in Older People.
Long-term health conditions often become worse
Hot weather places extra strain on the body.
People living with heart disease, asthma, COPD, kidney disease or diabetes often notice that symptoms become more difficult to manage during prolonged periods of heat.
Common problems include:
Increased breathlessness
Dizziness
Fatigue
Swollen ankles
Reduced urine output
Poor blood pressure control
Heat and dehydration can also affect how some medicines work.
If you have a long-term medical condition, staying hydrated and recognising early changes in your symptoms becomes even more important during hot weather.
Food poisoning
Food poisoning is another common summer illness.
Warm weather allows bacteria such as Campylobacter and Salmonella to multiply much more quickly if food is not stored or cooked properly.
Symptoms usually develop within hours or days and include:
Diarrhoea
Vomiting
Stomach cramps
Fever
Feeling generally unwell
Most people recover within a few days, but dehydration can become serious, particularly in young children, older adults and people with existing medical conditions.
Simple food hygiene makes a big difference:
Keep food refrigerated
Cook meat thoroughly
Wash your hands before preparing food
Avoid leaving food outside for long periods, especially during barbecues or picnics
If you are interested in learning more about gut health, see Food Poisoning and Gut Health.
Why GP practices are busier during summer
Many people expect GP surgeries to become quieter once winter ends.
That is no longer the reality.
Instead of winter viruses, we see increasing numbers of patients with heat-related illness, severe allergies, worsening asthma and flare-ups of existing medical conditions.
At the same time, general practice continues to care for an ageing population, patients waiting for hospital treatment and people living with multiple long-term conditions.
Summer also coincides with annual leave for many healthcare professionals, meaning demand often remains high while capacity is reduced.
For many practices, summer is simply a different type of busy.
The key takeaway
Summer is good for our health in many ways, but it also brings its own challenges.
The four problems I see most often are severe hay fever, heat exhaustion and dehydration, worsening long-term health conditions and food poisoning.
Most of these illnesses are preventable. Staying hydrated, managing allergies early, taking extra care during heatwaves and following good food hygiene can significantly reduce your risk.
The important thing is not to dismiss new symptoms as "just the heat." If something feels different from your normal, particularly if you are older or have an existing medical condition, it is always worth taking it seriously.
Disclaimer
This blog post provides general information only. It is not intended to provide instruction and you should not rely on this information to determine a diagnosis, prognosis or course of treatment. It should not be used in place of a professional consultation with a doctor.
The medical information is the personal opinion of the stated author(s). It is based on available evidence or, where no published evidence is available, on current medical opinion and practice.
Every effort is taken to ensure that the information contained in this website is accurate and complete. However, accuracy cannot be guaranteed – rapid advances in medicine may cause information contained here to become outdated, invalid or subject to debate.
The author(s) is/are not responsible for the results of your decisions resulting from the use of the information, including, but not limited to, your choosing to seek or not to seek professional medical care, or from choosing or not choosing specific treatment based on the information.
You should not disregard the advice of your physician or other qualified healthcare provider because of any information you read on this website. If you have any health care questions, please consult a relevant medical practitioner.
