tonsil blood test explained

Overview

A tonsil blood test is a simple blood test that helps doctors find out what is causing your tonsil infection or inflammation. It can show if you have a bacterial infection (like strep throat) or a viral infection (like glandular fever).

Yes, blood tests for tonsil infections are common, especially when symptoms are severe or when a sore throat does not get better with usual care.

Anyone with tonsil symptoms may need this test, but it is more often used for older children, teenagers, and adults.

Symptoms

Common symptoms

• sore throat
• red and swollen tonsils
• white or yellow coating on tonsils
• pain when swallowing
• fever
• swollen lymph nodes in the neck

Symptoms in children

• irritability and crying
• refusing to eat or drink
• drooling more than usual
• tummy ache or vomiting
• fever and chills

Symptoms in older adults

• severe sore throat
• difficulty swallowing
• high fever
• feeling very tired
• voice changes

Causes

Main causes

• Streptococcus bacteria (strep throat)
• Viruses such as Epstein-Barr virus (causing glandular fever)
• Other bacteria or viruses that infect the tonsils

Risk factors

• Close contact with someone who has a sore throat
• Weakened immune system
• Being a child or teenager
• Living in crowded conditions

When to see a doctor

See a doctor urgently if:

• If you have trouble breathing
• If you cannot swallow any liquids
• If you have a very high fever (above 101°F or 38.3°C) that does not improve
• If you have severe pain that makes it hard to open your mouth

Book a routine appointment if:

• Sore throat that lasts more than 2 days
• Fever over 100.4°F (38°C) for more than 48 hours
• Swollen tonsils with white patches
• Pain when swallowing that interferes with eating

Diagnosis

Your doctor will ask about your symptoms, look at your throat, and may order a blood test. Blood tests can check for signs of infection such as high white blood cell count, or specific antibodies to viruses or bacteria.

Tests that may be done

• Complete blood count (CBC) to see if there is an infection
• Rapid strep test (often a throat swab, but sometimes a blood test)
• Monospot test for glandular fever (Epstein-Barr virus)
• Antistreptolysin O titre (ASO) to check for recent strep infection

What to expect at your appointment

A healthcare professional will take a small sample of blood from your arm or fingertip. It is quick and causes only a brief pinch. The sample is sent to a lab and results may take a few days, depending on the test.

Treatment

Treatment depends on what is causing the infection. Bacterial infections are treated with antibiotics (medicine that kills bacteria), while viral infections need rest and self-care.

Self-care at home

• Drink plenty of fluids (water, warm tea)
• Get lots of rest
• Gargle with warm salt water (half a teaspoon of salt in a glass of water) to soothe your throat
• Eat soft, cool foods like ice cream or yogurt
• Use a humidifier or sit in a steamy bathroom to ease throat pain

Medical treatments

For bacterial tonsillitis, your doctor may prescribe a course of antibiotics. It is important to finish all the medicine, even if you start feeling better. For viral infections, treatment focuses on managing symptoms – your doctor may recommend over-the-counter pain relievers to reduce fever and pain. Always ask your pharmacist or doctor which type is safe for you and for the correct dose. Do not give aspirin to children.

When is surgery considered?

If someone gets tonsillitis many times or if the infection causes complications (like an abscess), a doctor may recommend a tonsillectomy. This is a common surgery to remove the tonsils. It is usually done in children and teenagers, but adults can have it too.

Living with this condition

If you have a tonsil infection, rest is important. Drink enough fluids so you don't get dehydrated. Avoid smoking or being around smoke. Keep up with hand washing to prevent spreading infection.

Lifestyle tips

• Stay home from work or school until the fever is gone and you feel better (usually 24-48 hours after starting antibiotics, if prescribed)
• Do not share cups, utensils, or toothbrushes
• Use a separate towel if possible
• Clean frequently touched surfaces

Diet and exercise

Eat soft, easy-to-swallow foods like soup, mashed potatoes, or smoothies. Avoid crunchy, spicy, or acidic foods that can irritate your throat. Gentle activity like walking is okay when you have energy, but rest more than usual.

Mental health and emotional wellbeing

Having a sore throat and fever can make you feel tired and low. It is normal to feel frustrated when you cannot eat or swallow comfortably. Give yourself time to recover. If you feel very anxious or down, talk to your doctor or a trusted person.

Prevention

You cannot completely prevent tonsil infections, but good hygiene can lower your risk. Wash your hands often, avoid close contact with people who are sick, do not share personal items, and keep your immune system strong with a healthy diet and enough sleep.

Vaccines

There is no vaccine for tonsillitis specifically. However, vaccines for flu and COVID-19 can help prevent viral infections that might lead to tonsillitis. The HPV vaccine can also prevent some throat cancers.

Screening programmes

There is no routine screening test for tonsil infections. Tests are only done if you have symptoms.

Complications

If left untreated

• Abscess (a pus-filled pocket near the tonsils) which may require drainage
• Dehydration from difficulty swallowing
• Spread of infection to nearby tissues (like the middle ear or sinuses)
• Rarely, rheumatic fever (from untreated strep throat) can affect the heart and joints

Long-term outlook

Most tonsil infections get better on their own or with treatment. Serious complications are rare. If you need surgery, recovery is usually straightforward. With proper care, you can expect a full recovery.

Find support

External links open third-party websites. Ruqelo Health is not responsible for external content. Listing an organisation does not imply endorsement.