I sneeze and have running nose as soon as i wake up after sleeping for some time.

Sounds like allergy: It sounds like you may be allergic to something in your sleeping environment. Check to see if you have feather pillows as allergy to those is common. Sometimes pillows also collect a lot of dust so maybe buying a new pillow and frequently washing the pillow case may help. If you sleep with animals that could also be the cause.

Allergies: You likely have an allergen in your bedroom, your bed and likely on your pillow. Wash everything in hot water without a detergent or change sheets. What is new in your environment? you can also try an OTC allergy medication such as Claritin (loratadine).