Diphtheria
Informed by recognized medical guidance
Overview
Diphtheria is a serious bacterial infection that usually affects the nose and throat. The bacteria make a poison (toxin) that can damage the body’s tissues, especially the throat and breathing passages. A thick gray coating can form in the throat, making it hard to breathe.
Key facts
- It is a bacterial infection that spreads from person to person through coughs, sneezes, or close contact.
- It can also spread by touching open sores (skin diphtheria).
- Diphtheria is rare in countries with high vaccination rates, but it can still happen in people who are not vaccinated.
- The infection can seriously harm the heart, nerves, and breathing.
- Early care with medicine greatly improves recovery.
Diphtheria is very rare in many parts of the world thanks to routine vaccination. However, it still occurs in some regions with low vaccination levels, and travellers can bring it back.
It can affect anyone who has not been vaccinated or is behind on vaccinations. The people at greatest risk are unvaccinated children, older adults, and people with weakened immune systems.
Symptoms
- Severe difficulty breathing
- Choking or a feeling that the throat is closing
- Blue or grey lips or skin
- Long periods of silence or no breathing
- Fainting or becoming very hard to wake
- ⚠A sore throat with a gray coating
- ⚠Difficulty swallowing saliva or liquids
- ⚠Swelling in the neck (bull neck)
- ⚠Fever with a fast heartbeat
Common symptoms
- Sore throat
- Mild fever
- Swollen glands in the neck
- A thick gray or white coating on the tonsils or back of the throat
- Difficulty swallowing
- Weakness and tiredness
Symptoms in children
- Same symptoms as adults
- Noisy or fast breathing
- A barking cough (like croup)
- Feeling very unwell quickly
Symptoms in older adults
- More severe breathing problems
- Increased risk of heart and nerve damage
- Confusion or extreme fatigue in some cases
Causes
Main causes
- Infection with a type of bacteria called Corynebacterium diphtheriae
- The bacteria make a toxin (poison) that damages the lining of the throat and other organs
Risk factors
- Not being vaccinated or not being up to date with vaccination
- Traveling to areas where diphtheria still occurs
- Living in crowded or unsanitary conditions
- Contact with an infected person or carrier (someone who carries the bacteria without symptoms)
- Weakened immune system due to other illness or medicines
When to see a doctor
See a doctor urgently if:
- You or your child has a sore throat plus a gray membrane or coating in the throat
- Difficult or noisy breathing
- Difficulty swallowing or drooling
- A swollen neck or a mumps-like look in the neck
Book a routine appointment if:
- You missed a scheduled vaccine dose or are unsure of your vaccination status
- You think you have been in close contact with someone who has diphtheria
- You have a persistent sore throat with swollen glands and feel unwell, even without a gray coating
Diagnosis
A doctor will ask about your symptoms, your vaccination history, and any travel or exposure. They will look in your throat for the gray coating. If they suspect diphtheria, they will take a swab from your throat or nose.
Tests that may be done
- Throat or nose swab to grow (culture) the bacteria in a lab
- PCR test, which looks for the bacteria’s genetic material
- Blood tests to look for signs of the toxin in the body
What to expect at your appointment
Because diphtheria can be serious, doctors often start treatment before test results come back. You may need to stay in the hospital for observation and to prevent spreading the infection to others.
Treatment
Diphtheria needs medical treatment as soon as possible. Doctors use medicines that neutralize the toxin and antibiotics that kill the bacteria. In hospital, you may receive supportive care to help with breathing, fluids, and monitoring of your heart.
Self-care at home
- Stay home and rest while you are being treated, to avoid spreading the infection
- Follow all isolation advice from your healthcare team
- Drink enough fluids to stay well hydrated
- Do not share food, cups, or utensils with others
- Wash your hands often, especially after contact with your nose or throat
Medical treatments
Treatment usually involves a medicine to stop the toxin from damaging the body, along with antibiotics to clear the infection. These are given by healthcare professionals in a hospital setting. You may also need medicines for fever or pain, but always ask your doctor or pharmacist which products are safe for you.
When is surgery considered?
Rarely, if the gray coating blocks the airway very severely, a doctor may need to do a procedure to open the windpipe so you can breathe. This is usually done in an emergency.
Living with this condition
During treatment, you will need to stay in the hospital for a while and then continue antibiotics at home. You may feel weak for several weeks. It is important to rest, eat well, and attend all follow-up appointments.
Lifestyle tips
- Complete the full course of medicine even if you feel better
- Avoid close contact with others until your doctor says you are not contagious
- Keep up to date with your vaccinations after recovery (ask your doctor)
- Practise good hygiene, like covering your mouth and nose when coughing or sneezing
Diet and exercise
Eat a balanced diet with soft foods if your throat is sore. Drink plenty of fluids, such as water or warm soup. Return to exercise gradually as your energy improves, and listen to your body.
Mental health and emotional wellbeing
Being ill with diphtheria and staying in hospital can be stressful and frightening. It is normal to feel anxious or low during recovery. Talk to your care team about your feelings, and contact your local mental health service if you need support.
Prevention
Yes, diphtheria is preventable with vaccination. Keeping up to date with recommended vaccines is the best way to protect yourself and your community.
Vaccines
The diphtheria vaccine is usually given combined with tetanus and whooping cough (pertussis) vaccines. It is part of routine childhood vaccination schedules in many countries. Ask your healthcare team about your own vaccination status and what is recommended for you.
Screening programmes
There is no routine screening for diphtheria in healthy people. However, if you have been in close contact with someone with diphtheria, a doctor may swab your throat to check if you carry the bacteria.
Complications
If left untreated
- Blockage in the airway, making it hard to breathe
- Heart damage, which can cause irregular heartbeats or heart failure
- Nerve damage, leading to weakness, numbness, or swallowing problems
- Kidney failure
- Death, although this is rare when treatment is given early
Long-term outlook
With early medical treatment, most people with diphtheria recover completely, though it may take several weeks to feel fully better. Some people have lasting effects, especially if the infection was severe or treatment was late. The best protection is vaccination.
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Always verify with your doctor
Health guidelines vary by country and region. The information in this article is based on international clinical guidelines but may not reflect the specific guidelines, medications, or practices in your country. Always discuss your health concerns with your own doctor or healthcare provider, and refer to your local national health guidelines where available.
Important notice This information is for educational purposes only. It does not replace professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider about your specific situation. If you are experiencing a medical emergency, call your local emergency services immediately.
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Sources and guidance
This article is educational and is prepared with reference to recognized health information and clinical guidance sources where available. Specific source links may vary by topic.
Last updated: July 31, 2026
Educational note: This information is for education only and is not a diagnosis.
Use it to support, not replace, advice from a licensed clinician.
If symptoms are severe, worsening, or urgent, call your local emergency number or seek emergency care.