Day time drowsiness is usually a manifestation of lack sound night sleep. It is important to rule out any insomnia features in night. Rule out any medical conditions like
diabetes or hypothyroidism or any substance misuse. More often depression can cause drowsiness, lethargy feelings. Only rarely some people experience excessive sleep due to hypersomnia due to Narcolepsy or other idiopathic causes. Please allow your Doctor to work out your diagnosis accordingly. Practice good sleep hygiene techniques. Read my blog about it on www.mindcarebangalore.com