A sudden hiccup occurs due to the involuntary spasms of the muscle called diaphragm.

The common reasons of hiccups includes eating or drinking too much, eating too quickly, abdominal surgery, strokes or brain tumors, noxious fumes, and certain medications.

In most cases hiccups get resolved by themselves in a short period of time and are rarely a          medical emergency is needed. If hiccups last more than three hours you need to see a doctor, or even if they disturb you’re eating or sleeping habits

Hiccups usually come at the most inconvenient times, and when you're in public or in a important meeting, you definitely need to know some very subtle methods to control them.  Try these seven times-tested easy techniques for stopping hiccups.

Use Your Hands

Press the palm of your hand with the thumb of your other hand as hard as you can. Another alternate, is that you can squeeze the ball of your left thumb between the thumb and forefinger of the right. The discomfort results in a distraction that affects your nervous system and leads to hiccups. It’s so simple that you can do it under the table without letting anyone notice you.

Cover Your Mouth

Cover your nose and mouth, without holding your breathe you can continue breathing normally. You'll get relief from hiccups from the extra dose of carbon dioxide.

Hold Your Breath

Take a deep breath and hold it. When carbon dioxide builds up of in your lungs, it helps to relax your diaphragm.

Plug Your Ears

Excuse yourself for a few minutes from all the work, and then stick your fingers in your ears for 20-30secs minimum. Instead you can also press the soft areas behind your earlobes, just below the skull’s base. By doing this, it sends a 'relax' signal via the nerve called as vagus, which is connected to the diaphragm.

Stick Out Your Tongue

You can stick out your tongue when no one around is watching you. This exercise is most practiced by singers and actors as it stimulates and results into the opening between the vocal cords. This helps you to breathe more smoothly and overcomes the spasms that cause hiccups.

Drink Some Water

Take small nine or ten quick sips in a row from a glass. When gulp down a drink, rhythmic contractions of the esophagus override spasms of the diaphragm.

Combine Tricks 3 and 6
If you block your ears while you drink, it’s all the way better. Stick your fingers in your ears and sip water though a straw. This will help you to get rid of hiccups as you’re pressing on the vagus nerve while you also get the benefit of steady swallowing.