This year the UK has experienced a particularly intense flu season, characterised by the emergence of the H3N2 “K” strain (often dubbed the “Superflu” in the media). This strain has led to an ‘earlier than usual’ surge in hospital admissions, which were reported to be 55% higher in December 2025 compared to the same period last year in 2024.
Below is a guide for you to help identify, manage, and know when to seek professional medical help for this flu season.
- Recognising the Symptoms
Flu-like symptoms such as fever, sore throat, nasal congestion, body aches and pains are typically caused by viruses. There are hundreds of viruses that can cause these symptoms, which usually lasts for 2-3 weeks. The first 5-7 days are generally the worst whilst the body’s immune system launches an immune response before you start to feel better.
Unlike the common cold, which develops gradually, flu symptoms typically appear suddenly and are far more debilitating.
| Symptom | Flu (Influenza) | Common Cold |
|---|---|---|
| Onset | Sudden (within hours) | Gradual (over days) |
| Fever | High (38°c) and persistent | Rare or mild |
| Fatigue | Severe; "can't get out of bed" | Mild; can usually keep active |
| Aches | Intense muscle/joint pain | Minimal |
| Cough | Dry, chesty, and hacking | Hacking or productive |
Specific Flu 2025 trends: The current H3N2 strain has been associated with significant gastrointestinal issues in some patients, including nausea, vomiting, and diarrhoea, alongside the traditional respiratory symptoms.
- Current UK Statistics (2025)
- Strain Dominance: The H3N2 subclade K is driving the majority of cases this winter. While not inherently more “deadly” than other strains, its rapid spread has increased the absolute number of severe cases.
- Hospital Impact: In mid-December 2025, an average of 2,660 patients per day were in hospital beds with flu—the highest level recorded for this time of year.
- Demographics: The highest positivity rates are currently seen in children aged 5 to 14 years, though the elderly remains the most vulnerable to complications.
- Management and Home Treatment
Most healthy adults can manage flu at home without a GP visit. The goal is to manage symptoms and prevent dehydration.
- Rest & Hydration: Your body needs energy to fight the virus. Drink plenty of water (your urine should be light yellow or clear).
- Medication: Paracetamol or Ibuprofen can help lower a fever and alleviate muscle aches. Please note: Avoid “double-dosing” by checking if your “All-in-One” flu remedies already contains paracetamol.
- Antivirals: In some instances, anti-viral medication, such as Oseltamivir (Tamiflu), may be prescribed. These do not “cure” the flu but can reduce the duration of illness by about 24 hours and lower the risk of complications if taken within 48 hours of symptom onset.
- When to Seek Medical Attention
While most recover within a week, flu can lead to secondary infections like pneumonia.
Contact a medical professional, if:
- Your symptoms do not improve after 7 days.
- You are in a “high-risk” group (ie. over 65, pregnant, or have a chronic condition like asthma or diabetes).
- You have a weakened immune system (ie. due to chemotherapy, immune-related condition).
- You are worried about a child or baby’s symptoms.
Seek Emergency Care (999 or A&E) if:
- You experience sudden chest pain.
- You have severe difficulty breathing (struggling to finish a sentence).
- You start coughing up blood.
A child becomes floppy, unresponsive, or develops a blue tint to the lips/skin
