From treating tonsillitis to sleep disorders, it’s all in a day’s work
for Dr John Loh.
One of the most basic
surgical skills that ear,
nose and throat (ENT)
specialists are trained
to perform is a tonsillectomy, or
the removal of the tonsils.
At Changi General Hospital
(CGH), Dr John Loh and other
ENT surgeons go through about
100 cases of adult tonsillectomies
every year, making up about a
third of the nation’s total cases.
“A viral or bacterial infection
may cause the tonsils to get
inflamed, which is a condition
known as tonsillitis. When
patients have chronic or recurrent
tonsillitis, a tonsillectomy is
recommended,” said Dr Loh,
Associate Consultant, Department
of Otorhinolaryngology – Head
and Neck Surgery, CGH.
Tonsils are a pair of ovalshaped
pads found at the back
of the throat and are part of the
body’s defence system to prevent
infections. A patient with tonsillitis
may experience severe sore throat,
high fever, or enlarged lymph nodes
that feel like lumps along the neck.
Although tonsillitis is a
common condition, Dr Loh
cautions against taking it lightly.
“Sometimes, the inflammation
can be serious enough to cause
airway obstruction or form
abscesses. We look out for danger
signs like difficulty in swallowing,
poor food and fluid intake,
dehydration, and difficult or noisy
breathing,” said Dr Loh.
He is also wary of asymmetrical
enlargement of one tonsil,
a non-healing ulcer, or enlarged
neck lymph nodes, which could be
signs of tonsil cancer.
Apart from tonsillitis, Dr Loh
manages a diverse range of
conditions affecting the head
and neck region, such as allergic
rhinitis, and cancers of the
thyroid, head and neck.
“I find the head and neck
region fascinating because of
the complex anatomy and close
proximity to many sensory
organs. I also have a particular
interest in sleep medicine and
surgery, as the effects of sleep
disorders are far-reaching.”
In the course of his work, he
has seen how sleep disorders,
such as snoring, upper airway
resistance syndrome and
obstructive sleep apnoea (OSA),
not only affect the quality of a
person’s sleep, but also cause
tiredness and fatigue during
daytime, and in some cases even
lead to higher risk of heart disease
Most people sleep for a third of
their life, and yet sleep disorders
tend to be under-diagnosed.
An especially challenging and as patients usually have several
co-existing medical problems
requiring the help of
a multidisciplinary team.
Dr Loh works with specialists
from the respiratory, psychiatry,
psychology and neurology
departments to ensure that
the care plan is individualised,
while taking into consideration
the patient’s anatomy and
“This way, we can achieve
optimised outcomes for the
patient,” said Dr Loh.
He once had a patient who was
barely getting an hour of quality
sleep every night due to OSA. A
home sleep study revealed that
complex condition to treat is OSA, he experienced severe drops in
oxygen levels caused by frequent
and repeated pauses in breathing
during sleep. While the levels
generally returned to normal once
regular breathing restarted,
Dr Loh knew frequent breathing
gaps can pose serious health
concerns. He then started the
patient on continuous positive
airway pressure (CPAP) treatment.
“After the treatment, the
patient felt energised with eight
hours of quality sleep, compared
to previously where he felt
lethargic even with more than 10
hours of sleep,” said Dr Loh.
Read more: Got sleep apnea? Here are quick tips for mild, moderate and severe.
It is moments like these
that give Dr Loh a sense of
satisfaction, knowing that he
has helped improve and resolve
On working days, Dr Loh is
in the hospital by 8am to do
his ward rounds, during which
he follows up on patients who
have been admitted for ENT
conditions. Once a week, he is in
the operating theatre to perform
Other than clinical duties, he
teaches medical students from the
National University of Singapore’s
Yong Loo Lin School of Medicine
and Nanyang Technological
University’s Lee Kong Chian School
of Medicine. He also mentors
“As a beneficiary of countless
hours of mentorship, I feel it is now
my responsibility to guide the next
generation of doctors and students
along their journey,” he said.
To unwind, Dr Loh enjoys
regular exercise and an occasional
glass of wine. While not quite
an adrenaline junkie, he used to
look forward to regular diving
and snowboarding trips overseas
before the COVID-19 pandemic.
These days, he has found a
different outlet in the form of
monthly jamming sessions with a
hobby band called ‘Haphazards’,
with whom he plays the drums.
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