The fact that I could not sleep last night led me to browsing the internet for something insomnia related and I ended up reading this article from Eons which discusses the disorder in depth.

What causes insomnia can be any of the follow below:

Excessive worrying

Illness — including painful arthritis, congestive heart failure that causes difficulty in breathing, and gastroesophageal reflux disease (GERD), among others.

Medications — for example, some drugs for hypertension and decongestants have stimulating effects; there are many others.

Consuming caffeine within six hours of bedtime. Lack of physical activity and/or exposure to natural outdoor light.

Sleep apnea, an obstruction of the airway, which can cause you to stop breathing repeatedly during the night. This forces the brain to keep waking you up to restart your breathing.

Restless legs syndrome (RLS) — which can make your legs so tingly that you feel an uncontrollable urge to move them.

Prostate problems, urinary incontinence, or or a urinary tract infection that makes you run to the bathroom several times a night.