Health experts have issued a warning over a potentially “life-threatening” illness that can be more common in hot weather. The UK Health Security Agency (UKHSA) has told people to “know the signs” of a urinary tract infection (UTI).

In a post made to X, the UKHSA said: “UTIs can cause life-threatening bloodstream infections, and contribute to antibiotic resistant infections. Untreated they can lead to hospitalisation, sepsis, and in the most serious cases death. Know the signs.”

UTIs are caused by bacteria infiltrating parts of the urinary system, including the urethra, bladder, or kidneys. Although most lower UTIs result in "mild discomfort" and can resolve independently or with antibiotics, they can escalate into more severe infections.

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10 key signs of a UTI to look for are:

• Pain or a burning sensation when urinating (dysuria)
• Needing to urinate more often than usual
• Needing to urinate more often than usual during the night (nocturia)
• Needing to urinate suddenly or more urgently than usual
• Urine that looks cloudy
• Blood in your urine
• Lower tummy pain or pain in your back, just under the ribs
• A high temperature, or feeling hot or cold, and shivery
• A very low temperature below 36C
• Feeling tired or weak

The NHS warns that your urine may also be dark or smell. “If this is your only symptom, it might be because you've not been drinking enough water,” it adds.

UTIs can be more common in the summer as they can be caused by dehydration. Some of the symptoms can vary depending on who is affected.

Symptoms in children can include:

• Having a high temperature – your child is feeling hotter than usual if you touch their neck, back or tummy
• Appearing generally unwell – babies and young children may be irritable and not feed, eat or drink properly
• Wetting the bed or wetting themselves
• Being sick

In older, frail people who have problems with memory, learning and concentration (such as dementia), and people with a urinary catheter, symptoms of a UTI may also include:

• Changes in behaviour, such as acting agitated or confused (delirium)
• Leaking urine (wetting themselves or incontinence) that is worse than usual
• New shivering or shaking (rigors)

The warning comes as figures show older people are worst affected by UTIs. According to data from the Hospital Episode Statistics (HES) database, there were close to 200,000 UTI-related hospital admissions in England during the 2023 to 2023 financial year, encompassing both community-acquired and hospital-acquired infections.

These admissions accounted for 1.2 million bed days, with an average stay of six days per infection, as reported by the UKHSA. The statistics underscore the significant burden UTIs place on the elderly and women.

The data reveals that 52.7 per cent of those admitted were aged over 70, and 61.8 per cent were female. While women under 50 years old are nearly five times more likely to be hospitalised for a UTI than men (24.7 per cent female versus 5.3 per cent male), the gender disparity narrows in those over 50, with 37.1 per cent female admissions compared to 32.9 per cent male.

The UKHSA emphasised: "This highlights the need for men over 50 to also pay early attention to urinary symptoms and seek treatment that may prevent hospitalisation."

Hospital admissions for UTIs hit a low in 2020 to 2021, likely due to the COVID-19 pandemic. However, since then, hospitalisations have seen an uptick, rising by nine per cent in 2023 to 2024 compared to the previous year. The UKHSA stressed that early detection and treatment of a UTI is "important".

People can reduce their risk of catching a UTI in the first place by:

• Drinking enough fluids regularly, especially in hot weather – more trips to the toilet may be needed, but that shouldn’t stop you drinking
• Avoiding holding pee - go to the toilet as soon as possible when you need to
• Washing, or shower daily where possible especially if you suffer from incontinence keep the genital area clean and dry, and check and change leakage of urine pads often
• Wiping from front to back after using the toilet to prevent bacteria from spreading
• Washing genitals before and after sex
• Talking to your healthcare professional if you have frequent UTIs, as they may be able to suggest treatments that could help

If you experience UTI symptoms you should speak to a pharmacist or your GP.