Why Do Bad Smells Make Us Feel Ill?

Most of the reasons for wanting to tackle smells caused by bodily fluids and incontinence quickly are as self-evident as the power of our enzyme-based cleaning sprays. 

Smells such as vomit, incontinence and body odour are often strong, unpleasant, and can linger for a remarkably long time, all of which make cleaning and removing the smell a priority for many people.

However, one important reason for getting rid of such smells, particularly in the case of vomit, is that it can also make people nearby feel ill themselves.

To understand why, it is important to understand why people feel sick in the first place, what makes smell such a powerful sensation in triggering illness and why it does not necessarily matter where the smell is coming from.

Why Do We Feel Sick From Smells?

Sickness is typically caused by nausea, a complex bodily system that is a vital part of how the body protects itself from potential poisons and toxic substances.

Nausea is extremely common, and almost everyone will have felt sick many times in their lives, but the link between smells and sickness is complex and typically comes from a mixture of chemical and psychological components.

What Smells Can Cause Nausea?

The most common reason why smells cause nausea is to protect the body from potential dangers, and this can manifest in multiple ways and can shape behaviour.

Certain foods and drinks can cause a nauseous reaction if a person has a previous bad experience with them. For example, if a person has a bad case of food poisoning from a particular meal, the brain will associate the smell of that food with danger.

This is a deliberate mechanism used by certain medications such as disulfiram to induce a nauseous response when it reacts to a certain substance such as alcohol.

However, in other cases, certain smells automatically produce that nauseous response even if you do not have a personal experience of illness, such as spoiled milk, mouldy food or rotten eggs.

The latter is deliberately used to save lives in the form of mercaptan, which smells extremely strong and foul to make it easy to detect the presence of natural gas, which would otherwise be odourless.

Why Do Bodily Smells Make Us Feel Nauseous?

Smells such as strong body odour, urine, faeces and vomit are especially unpleasant, and can cause nausea or even vomiting themselves when in strong enough combinations.

The reasons for this are somewhat related to why other smells make us feel ill, and nausea is typically a defence mechanism to protect us from potentially harmful substances.

The sense of smell and sense of taste are very closely linked, and because of this, the body cannot always tell the difference between strong tastes in the mouth and extremely strong smells.

Vomit consists of a range of foul-smelling substances, including partially digested food, bile and bacteria, all of which coalesce into a potential nauseous trigger. This is also true for other bodily fluids, but vomit can be particularly affecting.

This is why quick action to remove smells rather than simply masking them is essential.