Paresthesia, or sleeping limbs, is characterised by a numb, tingling, or a slight burning sensation in your limbs that usually affects hands, arms, and feet. It can also affect joints, pressure points and areas close to a nerve.

Science it out

So, how does this happen? Well, when you put pressure on a limb for too long — like sitting cross-legged for too long, sleeping on one arm, leaning on one elbow, or holding a phone or book in one position — this leads to temporary nerve compression or slowed down blood flow. When you finally remove pressure, nerves fire rapidly as they “restart”. The brain will interpret this as a pins-and-needles sensation. The sensation fades soon after movement continues.

It is also caused by bumping something (like your elbow) which can lead to a sharp, shooting-like feeling. That’s known as “hitting your funny bone,” or the ulnar nerve.

‘Underlying’ causes

Based on what causes paresthesia, there are two types of it: transient (temporary) and persistent.

Transient paresthesia is more common, and is often short-lived. It is caused by pressure on the limbs released after long hours. Some other causes include:

• Dehydration

• Hyperventilation

• Migraines, and

• Panic attacks

However, persistent paresthesia can be a sign of more serious conditions, like brain tumours, strokes, low blood sugar or thyroid function, vitamin deficiency, or autoimmune or inflammatory diseases.

Prevention

Temporary paresthesia can be fixed by changing postures more frequently. Stretch as often as possible and avoid putting too much pressure on your limbs. Of course, should it be persistent, you might want to see a doctor. It could be an underlying sign of a life-threatening condition.

Limbs don’t “fall asleep” in the true sense, your nerves are just squashed temporarily. Your body is essentially telling you to get up and get a move on. In most cases, it is an easy to prevent condition, but in rare cases, you’re being warned of something more serious. Either way, it’s just another quirky way for your nerves to send signals.

Hiccups are essentially involuntary contractions (or spasms) of the diaphragm, the muscle that aids us in breathing. Each contraction comes with a sudden closing of the vocal cords, creating that familiar sound we all know. There are multiple causes of hiccups. Some include eating too fast, drinking something too hot or too cold, swallowing air (usually while chewing gum), or just experiencing sudden changes in temperature.

The science behind

So, what happens to your body during hiccups? Your diaphragm goes through some repeated spasms when something irritates the nerves that cause the diaphragm to suddenly contract. These nerves make up something we call the reflex arc. Reflex arcs manage your body’s involuntary functions (like heart rate, breathing, and digestion). Meanwhile, the glottis, or your vocal cords, suddenly closes to stop more air from coming in. This is what makes that ‘hic’ sound.

Downing the hiccups

Most hiccups often fade out on their own with time, as the body naturally resets the breathing rhythm.

However, some cures like holding your breath, drinking water, or breathing into a paper bag can also help. These methods often increase the content of carbon dioxide, thereby calming the diaphragm down.

For when it gets bothersome

Short-term hiccups which last for less than 24 hours are somewhat harmless. However, persistent hiccups — which last for over 48 hours — often signal a problem. Persistent hiccups are often linked to the flu, gastrointestinal diseases, like GERD or gastritis; lung diseases like pneumonia; tumours, or even metabolism-related issues.

Persistent hiccups also lead to complications like:

• Trouble breathing, swallowing, or speaking

• Difficulty sleeping and excessive exhaustion, and

• Weight loss

However, these can be treated with medications and other methods like nerve blocks (an injection that may provide temporary pain relief). Leave it to a healthcare provider to prescribe the best medication. If a medication you’re taking is still giving you hiccups, your provider may tell you to stop taking it and take another instead. Never stop taking medication unless you’re told to.

Though hiccups may be an uninvited bodily guest, they remind us of how our body has its own unique ways of giving us calls for help. So the next time a sudden “hic!” interrupts your conversation, know that it’s your body briefly losing, and then finding its rhythm again.