Kissing And Your Health

Overview

Kissing is a normal, healthy part of close relationships. It helps people feel connected, and it can even lower stress. But kissing also means sharing saliva and tiny amounts of germs with another person. Most of the time that is completely harmless. Sometimes, though, kissing can pass on an infection — from the virus that causes cold sores to the one behind 'kissing disease' (glandular fever). Knowing what can spread this way helps you enjoy closeness and still look after your health.

Yes. Almost everyone kisses, and almost everyone picks up a cold sore or a throat infection at some point. Infections spread by kissing are among the most common infections people see their doctor about.

Anyone can be affected. Glandular fever is most common in teenagers and young adults, especially those in close contact with others such as at school or university. Cold sores often first appear in young children after being kissed by an adult with a sore. People with a weakened immune system, newborn babies and pregnant women need to be a little more careful, because infections that are mild for most people can be more serious for them.

Symptoms

Common symptoms

• A tingling, itching or burning spot on the lip a day or two before a cold sore appears
• Small fluid-filled blisters on or around the lips that crust over and heal
• Sore throat, sometimes with white patches on the tonsils
• Swollen, tender glands in the neck
• Fever and feeling generally unwell
• Unusual tiredness that can last for several weeks
• Mouth ulcers or a sore mouth
• Cold-like symptoms such as a runny nose, sneezing or cough
• A rash along with fever in some viral illnesses

Symptoms in children

• Cold sores around the mouth after being kissed by an adult with a sore — avoid kissing babies on the mouth
• Blisters on the hands, feet and in the mouth with hand, foot and mouth disease, which spreads easily through close contact
• Fever, drooling and refusing food or drink because of a sore mouth
• Being clingy or irritable and sleeping more than usual
• Teenagers may get glandular fever with a sore throat, swollen glands and weeks of tiredness

Symptoms in older adults

• Cold sores can take longer to heal and may come back more often
• The chickenpox virus, which stays in the body for life, can wake up later as shingles — this is caught from contact with a shingles rash, not from kissing
• A dry mouth or dentures can make small mouth infections more likely
• Some medicines and health conditions lower the body's defences, so infections may last longer
• It is worth checking in with a doctor if a sore or fever does not settle as expected

Causes

Main causes

• Viruses carried in saliva — such as the cold sore virus (herpes simplex type 1), the glandular fever virus (Epstein-Barr virus), common cold and flu viruses, COVID-19, and the viruses that cause hand, foot and mouth disease
• Bacteria that live in the mouth and throat, including those behind some throat infections and, rarely, serious illnesses like meningitis
• Fungi such as thrush, which are more likely in people with a weakened immune system or a dry mouth
• Some infections, such as syphilis or gonorrhoea, can pass between mouths during oral sex — this is different from everyday kissing
• Rarely, an allergic reaction to tiny traces of food or medicine in a partner's saliva, or irritation from lip balm, make-up or stubble

Risk factors

• Kissing someone who has a visible cold sore or is unwell with a fever or sore throat
• Having a new partner or more than one partner
• A weakened immune system, from illness or certain medicines
• Pregnancy — some viruses, such as CMV, can affect a baby, so extra care with hygiene is wise
• Being a newborn baby or a young child, whose defences are still developing
• Smoking, heavy drinking or poor sleep, which can make it harder to fight infections
• A dry mouth or poor mouth hygiene
• Living or studying in close quarters, such as student halls, where infections spread easily

When to see a doctor

See a doctor urgently if:

• A cold sore in or near the eye, or any new eye pain, redness or blurred vision
• A cold sore in a newborn baby or someone with a weakened immune system
• Fever with a stiff neck, severe headache, confusion or a rash that does not fade when pressed
• Not able to swallow fluids, or signs of dehydration such as dark urine, dizziness or sunken eyes

Book a routine appointment if:

• Cold sores that keep coming back, or that are large or slow to heal
• A mouth ulcer that has not healed after three weeks
• Swollen neck glands lasting more than two to three weeks
• Tiredness that goes on for weeks and affects daily life
• White patches in the mouth, or a mouth that feels sore most of the time
• Any worry about a sexually transmitted infection, or questions about safer oral sex

Diagnosis

There is no test for kissing itself. If you feel unwell after close contact, a doctor will usually ask about your symptoms and when they started, look inside your mouth and throat, and gently feel the glands in your neck. Many of these infections can be recognised from the story and the examination alone.

Tests that may be done

• A throat swab — a soft cotton bud wiped at the back of the throat
• A blood test to check for glandular fever and to look at your blood cells
• A swab or sample from a blister or sore
• Sexual health tests, such as a swab or urine test, if oral sex may have been involved
• Rarely, allergy testing if a reaction happens each time after kissing

What to expect at your appointment

Most checks are quick and painless, and you can go home straight afterwards. Some results come back the same day, while blood tests can take a few days. You can ask what the tests are for and when to expect the results. Nothing you say will shock your doctor — they talk about these things every day.

Treatment

Most illnesses passed on by kissing get better on their own within one to two weeks. Treatment is mainly about easing symptoms, resting and letting your body fight the infection. A pharmacist can advise on simple ways to feel more comfortable, and a doctor can step in if an infection is more severe or you are in a higher-risk group.

Self-care at home

• Rest and drink plenty of fluids — water, squash or warm drinks are all fine
• Choose soft, cool foods if your throat or mouth is sore
• Gargle with warm salt water to ease a sore throat
• Keep lips moist with a plain lip balm and try not to pick at a cold sore
• Ask a pharmacist about over-the-counter pain relief and treatments for cold sores
• Wash your hands often, and avoid sharing drinks, lip balm, towels or toothbrushes
• Pause kissing while you have an active sore or feel unwell, and let your partner know why
• Use a lip balm with sun protection, as sunlight can trigger cold sores

Medical treatments

For some infections a doctor may prescribe medicine. Antiviral treatment can help cold sores, especially when started in the first day or two, and may be used for more severe viral illness or for people whose immune system is weaker. Antibiotics only work on bacterial infections, so they are not used for viral ones. If you are pregnant, have a weakened immune system, or a newborn is involved, doctors may choose to treat earlier and more actively. Always follow the advice of your own clinician rather than a friend's leftover medicine.

Living with this condition

Life with the odd cold sore or throat infection is very manageable. Learn your early warning signs — that tingle before a sore appears — so you can start a pharmacist-recommended treatment early and avoid kissing until it has crusted over. Tell partners honestly; most people understand, because almost everyone gets cold sores. Keep the whole thing in perspective: these are common, treatable problems, not a sign that something is wrong with you.

Lifestyle tips

• Aim for regular sleep, as tiredness makes infections more likely and recovery slower
• Brush your teeth twice a day and clean between your teeth — healthy gums help keep mouth infections away
• Do not share lip products, drinks or toothbrushes, even with people you are close to
• If you have oral sex, use a condom or dental dam to lower the chance of passing on sexually transmitted infections
• Wash your hands before touching your lips or eyes, especially if you have a sore
• Avoid close kissing when you or your partner have an active sore, a fever or a bad sore throat

Diet and exercise

There is no special diet that stops cold sores, but eating well and staying hydrated helps your body fight infections. Include plenty of fruit, vegetables, whole grains and protein, and drink water through the day. Regular activity you enjoy — a walk, a swim, a bike ride — supports your immune system and lifts your mood. If your mouth is sore, softer foods and cool drinks are easier to manage.

Mental health and emotional wellbeing

Worry about catching something, or about telling a partner you have a cold sore, can feel stressful. Some people feel embarrassed about sexually transmitted infections or about visible sores, and that can affect confidence and relationships. These feelings are common and treatable. Talking openly with a partner, a trusted friend, or a doctor or sexual health clinic often helps a lot. If low mood, anxiety or worry is affecting your sleep, work or relationships, please speak to your doctor. If you ever have thoughts of harming yourself, contact your local crisis line or your local emergency number straight away — help is available and you deserve it.

Prevention

You cannot make kissing completely risk-free, and you do not need to try. But you can lower the chances of passing on infections: avoid kissing someone with a visible cold sore or a feverish illness, do not share drinks, lip balm or toothbrushes, wash your hands often, and avoid kissing newborn babies on or near the mouth. Small habits make a real difference without taking the joy out of closeness.

Vaccines

There is no vaccine for cold sores or glandular fever. Seasonal flu and COVID-19 vaccines, where offered to you, reduce the chance of those illnesses and of passing them on. Ask your doctor or pharmacist whether you are due any vaccinations.

Screening programmes

There is no routine screening test for infections passed by kissing. Sexual health checks are free and confidential in most services if you are worried about a sexually transmitted infection, and regular dental check-ups help spot mouth problems early. If you are pregnant or planning a pregnancy and you get cold sores, mention it to your midwife or doctor so they can advise you.

Complications

If left untreated

• Dehydration from a sore throat or mouth ulcers that make drinking painful
• A cold sore that spreads to the eye, which can affect sight if not treated quickly
• A bacterial infection on top of a cold sore, with spreading redness, pain or pus
• A cold sore spreading widely on the skin in people with eczema
• Long-lasting tiredness from glandular fever, sometimes for several weeks or months
• In newborn babies and people with a weakened immune system, these infections can be more serious and need prompt treatment
• Rarely, a serious infection such as meningitis
• Time off school, university or work while you recover

Long-term outlook

For the great majority of people the outlook is very good. Cold sores are a nuisance that come and go, and glandular fever usually passes with rest, even if tiredness lingers for a while. Serious complications are uncommon, and the simple steps above lower your risk further. Most people find they can carry on enjoying close relationships with a little care and a bit of planning.

Find support

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