Reflecting on life in 1920s New York, F Scott Fitzgerald opined that “the hangover became a part of the day as well allowed-for as the Spanish siesta”. But while 21st-century bosses may not be quite as accommodating as the Wall Street tycoons of the roaring 20s, hangovers are certainly part of the Christmas party season.

Whether it’s how to avoid them in the first place or negating the suffering after the event, hangovers have been pondered over for millennia. In ancient Rome, Pliny the Elder declared it advisable to line the stomach with a meal of roasted sheep’s intestines before hitting the drink, while centuries later the English herbalist and botanist Nicholas Culpeper wrote that hangovers could be relieved by stuffing the nasal passages with the juice of tree ivy. However, despite having socio-economic consequences higher than many common diseases in terms of absenteeism and reduced work productivity, it is only relatively recently that hangovers have been considered worthy of serious scientific study.

Why are they called hangovers?

The hangover was first described more than 3,000 years ago in the Susruta Samhita, an Indian textbook on vedic medication. It was described as paramada, a post-drinking condition characterised by thirst, pain in the head and joints, and heaviness of the body, with no known cure.

But the word hangover has only become associated with alcohol in the past century. It first appeared in the English vocabulary in the 19th century as an expression for describing unfinished business from meetings, but it was not until 1904 that the word began to crop up in reference to alcohol.

What causes them?

Hangovers develop when blood-alcohol content returns to zero, leading to headaches, nausea, anxiety, dry mouth, sweating, gastro-intestinal complaints, concentration problems, dizziness, drowsiness and hyper-excitability. One of the causes is the way that the body metabolises the compounds found in alcoholic drinks. Alcoholic drinks contain very small amounts of methanol (in addition to ethanol), which the body breaks down into the toxins formaldehyde and formic acid about 10 hours after drinking, making you feel ill.

Another long-standing scientific theory has been that hangover symptoms are down to dehydration, because alcohol decreases the production of an anti-diuretic hormone, something the body requires to reabsorb water. With less of it available, the body loses fluid through urination. Yet, while hormonal changes resulting from a dehydrated state do cause dry mouth and thirst, studies on the biological changes present the day after excessive drinking suggest it isn’t quite that simple. Many of the cognitive alcohol hangover symptoms – such as memory loss, mood changes and anxiety – appear to be down to the effects of immune system activation and its impact on the central nervous system. As the body tries to process the alcohol metabolites in the bloodstream, it produces tiny molecules called cytokines. Cytokine receptors are particularly dense in the hippocampus, a brain structure crucial to memory function, and some studies have shown that increased cerebral cytokine concentration can cause weakness, decreased appetite, sickness and inability to concentrate.

Why do some people not get them?

It has been reported that 28% of drinkers say they never experience a hangover. The exact reasons why are little understood, as even when alcohol exposure is monitored under experimental conditions, there are considerable individual differences in terms of hangover response. It is thought to be down to a mix of genetic and environmental factors. Two genotypes – ADH1B and ALDH2 – are associated with the flushing or blotching response on the face or body following alcohol consumption, and have been found to be related to heightened hangover susceptibility. Some studies also show that heavy hangovers are more common in drinkers with a family history of alcoholism, with alcoholics getting the worst hangovers of all.

Can consistent hangovers have long-term consequences?

Yes. The pathophysiology of why this occurs is not fully known but various studies of university students have found a link between frequent hangovers and adverse neurocognitive outcomes such as decreased white-matter integrity in the frontal part of the brain and the cerebellum, which plays an important role in motor control. It is thought that the former could lead to sustained impairments in memory and attention span.

Does a ‘full English’ the next day really help?

Fried food can make you feel better. Drinking alcohol lowers your blood-sugar levels and eating a carbohydrate-heavy meal can help restore these to normal.

Do they worsen with age?

The common belief is that hangover symptoms become more severe with advancing age, possibly due to the body becoming less efficient at processing alcohol, but, from a scientific viewpoint, there’s little evidence to show that this is true. This is mainly because hangover research is almost entirely carried out on young adults, but the few studies that have been done comparing age groups find that post binge-drinking hangovers are worst in younger people.

Is there a ‘miracle cure’?

The quest for a hangover cure is about as old as recorded history. The oldest known cure is the “hair of the dog”, which does have a biological basis. If you continue drinking alcohol during the hangover phase, your body will stop metabolising methanol into toxins, and go back to processing ethanol, leaving the methanol for later.

But when it comes to dealing with the inevitable, various substances have been tried and tested over the centuries. The Romans recommended raw owls’ eggs, which may have had some beneficial effects, as eggs contain cysteine, an amino acid depleted by alcohol. The ancient Assyrians chose to consume a more dubious concoction of ground birds’ beaks and myrrh. In the era of Genghis Khan, Mongol warriors ate pickled sheep eyes, while in medieval Europe physicians recommended raw eels and bitter almonds.

More recently, a number of companies – no doubt thinking of the vast commercial potential – have tried to develop a valid hangover medication. But while various anti-inflammatories – such as the migraine drug, tolfenamic acid, or herbs such as borage – have shown some benefits, so far no treatments have received FDA approval as scientifically valid hangover cures.