Headaches!
We have all had them. There are many causes of headaches but this article
relates to that arising from conditions that affect the nose and sinuses. Our
nose is very sensitive. It has to be as it forms one of our earliest sense
organ for finding food as well as arousing us to the presence of danger from
predators or our changing environment. Many of us know the nose as an organ of
smell (and therefore flavor) and this sensation comes from the olfactory nerve.
The nose however has another nerve supply that provides us with the sensation
of heat, cold, dry, humid and of course, pain. This sensation arises from the
fifth nerve of our brain called the trigeminal nerve.
You all
know this nerve, which innervates your face, eyes, nose, sinuses and teeth. It
burns and gives you a headache if you do somersaults underwater in the swimming
pool or take too much wasabi on your sushi. Your face burns from the inside and
your eyes water. This is when your trigeminal nerve is being hyper-stimulated.
This same
nerve is responsible for the headaches one can get from sino-nasal disease. If
someone has nasal allergy, and especially if the septum (the bone inside your
nose that separates the right from the left nostril) is bent, the lining of the
nose expands considerably. When the hypersensitive linings touches one another,
they can cause a localized headache at the top of the head, the temples or the
back of the head. This kind of headache, or nerve pain, is known as Sluder’s
neuralgia or Sluder’s headache.
Our
sinuses are air-filled cavities inside our skull. These cavities have very
narrow openings into the nose. Again, due to:
· a nose allergy,
· a bent septum blocking the sinus
opening,
· a narrowed sinus opening/s from
recurrent infection
· or all of the above in the same person
at the same time,
The sinus
opening/s become blocked. When this happens, a negative pressure is generated
within the sinus and this can cause facial pains and headaches. If, on the
other hand, there is a bacterial infection with pus formation, the pus will
build up an intense pressure from within the sinus causing pain too. This
change in pressure stimulates the nerve endings in the nose and sinuses,
causing a sinus headache.
If only
specific sinuses are affected like the frontal sinuses above the eyes, then a
headache above and behind the eye may be felt.
Sinus headaches are peculiar in that the pain changes in intensity with
position, being usually more painful when the head is lowered i.e. tying the
shoelaces or picking something from the floor. Also the bony surface of the
face just outside the inflamed sinus is painful to applied pressure from
outside the face.
Naturally,
as you now understand that sino-nasal inflammation can cause headaches, you
will realize that any infection of the inside of the nose can do this too. Even
when we are stressed, the nose lining inside swells up and this can manifest as
a headache. Equally cancers of the nose, sinuses and nasopharynx can cause
headaches as they stimulate the trigeminal nerve or block the sinus openings.
Cancers are thankfully much, much less common than allergies. However in any
case, any persistent or recurring headaches is best investigated for its cause
and the correct treatment offered.
The Chinese
version of this article was published in Hong Kong Economic Journal on 22 Dec 2014
