Fever in older adults

Overview

Fever is a temporary rise in body temperature, usually because the body is fighting an infection. In older adults, fever can sometimes be less obvious or lower, but it is still an important sign that something might be wrong. It is one of the body's natural defense mechanisms.

Yes, fever is quite common in older adults, especially when they have an infection. However, it can be easy to miss because the temperature rise might be small and other symptoms like confusion may be mistaken for dementia or aging.

Fever can affect anyone, but it is especially important in people aged 65 and older because their immune systems are often weaker, and they may have other health conditions that increase risk of complications.

Symptoms

Common symptoms

• Chills
• Sweating
• Headache
• Muscle aches
• Feeling tired or weak

Symptoms in children

• High temperature (often over 38°C or 100.4°F)
• Irritability or fussiness
• Vomiting or diarrhea
• Loss of appetite
• Rash

Symptoms in older adults

• Confusion or sudden change in mental state
• Weakness or feeling very tired
• Loss of appetite
• Lower temperature rise (for example, 37.2°C to 38.3°C or 99°F to 101°F)
• Rapid breathing or fast heart rate
• Shivering or feeling cold when others are warm

Causes

Main causes

• Bacterial infections such as urinary tract infections, pneumonia, skin infections, or infections of the blood
• Viral infections like influenza, COVID-19, or respiratory syncytial virus (RSV)
• Heat-related illness like heat exhaustion or heat stroke
• Some medications, including certain antibiotics or drugs used for arthritis
• Inflammatory conditions such as rheumatoid arthritis or vasculitis

Risk factors

• Age 65 years or older
• Chronic diseases like diabetes, heart disease, or lung disease
• Weakened immune system due to conditions like cancer, HIV, or long-term steroid use
• Living in a care home or nursing facility
• Recent hospitalization or surgery
• Having a urinary catheter or other medical devices

When to see a doctor

See a doctor urgently if:

• Fever higher than 38.5°C (101.3°F) that does not respond to simple measures
• New confusion or drowsiness
• Difficulty breathing or rapid breathing
• Severe headache or stiff neck
• Signs of dehydration such as dizziness or not passing urine
• Fever with a rash that does not fade when pressed

Book a routine appointment if:

• Fever between 37.5°C and 38.5°C (99.5°F to 101.3°F) that lasts more than 48 hours
• Mild fever with mild cough or other mild symptoms that do not improve
• If you have recently started a new medication and have a low-grade fever

Diagnosis

The doctor will take the person’s temperature, ask about symptoms and medical history, and perform a physical examination. They will look for signs of infection and may ask about recent travel, medications, and any other health changes.

Tests that may be done

• Blood tests to check for signs of infection, inflammation, or organ function
• Urine test to check for a urinary tract infection
• Chest X-ray if pneumonia is suspected
• Cultures of blood, urine, or sputum to find the specific germ causing the infection
• Other imaging scans or tests based on symptoms

What to expect at your appointment

The doctor will work to find the cause of the fever and may start treatment quickly, especially if an infection is suspected. You may need to go to the hospital if the fever is high or if there are signs of a serious infection. The doctor will monitor vital signs and may recommend staying in for observation or treatment.

Treatment

Treatment focuses on finding and addressing the underlying cause of the fever—usually an infection—and helping the body recover. In many cases, fever can be managed at home with rest and fluids, but if the cause is a bacterial infection, antibiotics may be prescribed. The goal is to reduce discomfort and prevent complications.

Self-care at home

• Rest as much as possible to help your body fight the infection.
• Drink plenty of fluids such as water, clear soup, or oral rehydration drinks to prevent dehydration.
• Use a fan or open window to keep the room comfortably cool, but avoid getting chilled.
• Wear lightweight clothing and use light bedding.
• Monitor your temperature regularly and note any other symptoms.

Medical treatments

If a bacterial infection is found, your doctor will prescribe antibiotics to take as directed. For viral infections, antiviral medications may be considered in certain cases. Never take leftover antibiotics or share them with others. If the fever is very high or causing severe symptoms, the doctor may recommend medication to bring the fever down—always use as directed and ask your pharmacist about options. In hospital, you may receive intravenous fluids or other supportive treatments.

When is surgery considered?

Surgery is rarely needed for fever itself. However, if an infection has caused an abscess (a collection of pus) that needs draining, a small surgical procedure may be required. This is not common for most fevers.

Living with this condition

During a fever, the main priority is rest and recovery. Monitor your temperature and other symptoms closely. Keep a record to share with your doctor. Stay in touch with family or friends to get help with daily tasks if needed. Once the fever resolves, gradually return to normal activities as your strength allows.

Lifestyle tips

• Get enough sleep and avoid overexerting yourself until you feel fully recovered.
• Practice good hygiene like washing hands regularly to prevent spreading infections.
• Keep your living space clean and well-ventilated.
• Avoid alcohol and smoking as they can affect your immune system and hydration.

Diet and exercise

While you have a fever, eat light, easy-to-digest foods like soups, broths, and toast if you have an appetite. Drink plenty of fluids to stay hydrated. Gentle stretching or short walks can be resumed when you feel better, but avoid vigorous exercise until the fever is gone and you have regained strength.

Mental health and emotional wellbeing

Having a fever can be stressful, especially if you feel confused or anxious. It is normal to feel worried. Talk to your doctor or a trusted person about your concerns. If confusion persists after the fever goes away, seek medical advice. For mental health crisis, contact a crisis support line immediately.

Prevention

Not all fevers can be prevented, but the risk of infections can be reduced with good hygiene, staying up to date on vaccinations, and avoiding close contact with sick people. Keeping chronic conditions well-managed also helps your immune system stay strong.

Vaccines

Vaccines are recommended for older adults to prevent certain infections that cause fever. These include the flu vaccine, pneumonia vaccine, and shingles vaccine. Ask your doctor which vaccines are right for you.

Screening programmes

There are no routine screening tests specifically for fever, but regular check-ups can help detect and manage underlying health conditions that increase infection risk. If you have symptoms, seek medical advice early.

Complications

If left untreated

• Sepsis (a life-threatening response to infection that can cause organ failure)
• Dehydration, which can stress the kidneys and heart
• Confusion or delirium that may become prolonged
• Worsening of underlying chronic conditions such as heart failure or diabetes
• Seizures (rare in older adults, but possible)

Long-term outlook

With timely care, most older adults recover fully from a fever without long-term problems. Early treatment of the underlying cause, especially infections, greatly improves outcomes. It is important to act quickly if you notice changes in mental state or other warning signs. Most fevers are treatable, and your healthcare team will support you to get back to your usual health.

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