Hello dear!.
I would like to have a detailed history regarding the symptoms
Is your child a mouth breather?
Do you have a family history of
asthma and allergy?
The symptoms which you have told possibly suggest your child has
adenoid hypertrophy.
Its not the usual age for adenoid removal.
Till then you have to treat him symptomatically.
Give him a good anti
histamine like Levocetrizine 5 ml at night , monteleukast sachet 4 mg,dissolved in water ,give at night (both these for 3 months).
Keep his head a little higher and place a pillow below neck to keep airway open to make his breathing comfortable.
You can also try some
home remedies like one teaspoon of honey in a glass of luke warm water given once a day.
Give normal saline nebulization or steam inhalation at bed time.
Hope it will help.Wishing your child good health :-)