What causes different sweet smelling urine?
There are various causes of sweet smell in the urine. Most are
transient and due to metabolizing various foods. Sometimes strong
odor is due to highly concentrated urine when one hasn't consumed
enough water, easily fixed. Another cause is sweet smell due to
uncontrolled diabetes melitus, which can be determined through
urinalysis evaluated by a physician.
There is a rare metabolic disease called Mapple Syrup Urine
Disease , as the smell is like slightly burnt sugar - or for people
who have actually smelt mapple syrup, that is apparently what the
urine smell is similar to. The incidence of this illness is around
one in 200.000 births, with the exception of a small intermarrying
community of Northern European descent in the USA where the
incidence is much higher. This neurological condition effects
infants and children and would not present in adults.
MSUD, as it is known, is a condition where the body can't deal
with substances called branched aminoacids. One of these, called
leucine is toxic, in particular to the brain. There are various
types of the disease, symptoms range from brain disfunction and
death in the newborn period to very mild indeed. Many children will
have mental retardation, even if their MSUD is discovered early and
the metabolic doctors that care for them put them on the special
protective diet at a very young age.
Some very fortunate children are known to have normal
intelligence, this requires very good metabolic control throughout
Other causes of sweet smell in the urine are very rare indeed.
One should have a talk with a doctor who specialises in metabolic
medicine if one is concerned that urine smells very different to
the usual. The tests to find out what is wrong and the methods to
fix the problem are very complex.