What causes bad breath
‘Morning
breath’. Almost
everyone has bad breath first thing in the morning. During
the day, movement of the tongue and cheeks dislodges food
debris and dead cells, and these are washed away by saliva.
While we are asleep our tongue and cheeks do not move much,
and the flow of saliva is reduced. The food residues stagnate
in the mouth, and mouth bacteria rapidly break them down,
releasing an unpleasant stale smell. Breathing through the
mouth when sleeping tends to make this worse. Morning breath
normally disappears after breakfast, cleaning the teeth or
rinsing the mouth with water. Get your saliva going with
a drink of water and lemon.
Temporary bad breath is the lingering
effect of cigarettes or something you have eaten or drunk
in the past 24–48 hours. Alcohol, onions, cabbage,
broccoli, radish, durian, garlic, curries and other highly
spiced foods, cured foods such as salamis, and smoked foods
such as kippers are particularly likely to remain on the
breath. The problem is not simply that the smells stay in
the mouth. These foods are digested and then broken down
in the body, and the breakdown products of some, particularly
alcohol, onions and garlic, are expelled in the breath for
hours or days afterwards. (This is the basis of the ‘breathalyser
test’ for alcohol.)
Smoking also reduces the flow of saliva, which makes its
smell linger even longer.
Traditional remedies (such as eating parsley) can help,
and mouth fresheners disguise the smell. Clean your mouth
by rinsing it thoroughly with warm water, giving it a good
brushing with toothpaste and then rinsing thoroughly again.
Bad breath can even result from not eating. When no food
is available, the body starts breaking down fat. Waste products
from fat breakdown, called ketones, are expelled in the breath,
and smell like stale apples.
Persistent bad breath
Gum disease,
according to dentists, is the usual cause of persistent bad
breath. Gum disease is not always painful, so we may not
know we have it. The gum is likely to bleed when you brush
your teeth. It will look very red, but goes pale for a moment
if you press on it, and will be slightly swollen where it
meets the teeth. Gum disease is caused by ‘plaque’,
the sticky film of bacteria that naturally forms on the teeth
of everyone every day. These bacteria tend to lodge between
the teeth and where the teeth meet the gum. The waste products
of the bacteria have a foul, stale smell. Apart from bad
breath, gum disease can eventually cause loosening of the
teeth.
Poor oral hygiene is an obvious cause.
If you do not clean your teeth, you will soon develop bad
breath.
Bacteria on the back of the tongue are one of the most
common causes of bad breath. Food particles, postnasal drip
and stagnant saliva build up in the ‘fur’ at
the back of the tongue, providing a breeding ground for bacteria.
These bacteria produce many nasty-smelling chemicals.
Postnasal drip can cause bad breath. This
is mucus that trickles down the back of the throat. The reason
for the mucus is inflammation in the air passages behind
the nose because of allergies or a sinus infection. It often
causes a ticklish cough, particularly when lying flat at
night. This type of bad breath is worst when the person is
speaking.
Anything that dries the mouth makes bad
breath worse, because saliva cleanses the mouth. Tricyclic
antidepressant drugs (such as amitriptyline) reduce saliva.
Alcohol, alcohol-containing mouthwashes, heavy exercise and
fasting can all result in a dry mouth and worsen a bad breath
problem.
Isosorbide dinitrate, a drug for angina,
sometimes produces an objectionable smell in the mouth.
Gut problems used to be blamed, and enemas
and laxatives were often given as cures, but in fact these
have very little to do with bad breath. Your stomach is shut
off from your throat and mouth by a tight ring of muscle
at the base of the food pipe (oesophagus), so it is normally
a closed tube. Therefore no odour escapes from the stomach,
except if you belch, or regurgitate food (vomit).
Chest problems, such as obstructive airways
disease (chronic bronchitis), can cause bad breath.
Bad breath in a small child may mean that the child has inserted
a small object (such as a seed or small toy) into the nose,
where it has stuck and caused an infection. For this reason,
small children with bad breath should be seen by a doctor.