The Difference Between Signs and Symptoms

The Difference Between Signs and Symptoms

In first aid we very often talk about signs and symptoms, and these are often lumped together in one phrase, almost as if they are the same thing really. However they are quite different, so in this post we’re going to explain the difference between signs and symptoms, and how this might affect your first aid practice.

We can see signs that this woman doesn’t look happy, but what are the symptoms she is experiencing?

So, what is the difference between signs and symptoms?



Simply put, a sign is something that you as the first aider can see, hear, feel, or smell.  Something on the casualty that you can use your own senses to measure, or monitor.


Visual clues can tell us a lot.  Is the casualty guarding an injury, or maybe rubbing their temples? Does the injured area look swollen, or discoloured?  Is the casualty sweating or shivering?  Remember to always Compare and Contrast where possible – especially with injuries – is one knee more swollen than the other for example? Other visual clues might be signs or mechanisms of injury on approach, is there obvious damage? Can you see blood?


Using touch can give us further information, particularly where swelling is involved.  Again, Comparing and Contrasting where possible, does the injured area feel swollen, warm, tight?  Feel can also tell us about temperature. The casualty may look hot or cold, but do they feel hot or cold to the touch? We can also use feel as one way of monitoring a casualty’s breathing.


Using our hearing is a little more subtle, and can be very difficult in a noisy environment. However, we may hear that a casualties breathing is restricted for example – it may sound raspy, or make a gurgling sound.  In the case of an injury, the casualty may report that they heard a popping sound.


Smell is also more subtle but can give us more clues as to the history of the incident.  Can you smell alcohol on a casualty’s breath, or is there a sweet fruity smell?  Has the casualty been incontinent? Paired with the other signs, this could suggest a variety of issues.



Symptoms are things that the casualty is experiencing. They are possibly less obvious to you as the first aider, but are things that the casualty tells you about, or indicates to you in another way if they are not fully conscious, or are a baby and aren’t able to talk yet.

From a selection of the examples above:

You can see that the casualty is rubbing their temples.  Can they describe their headache – is it a dull ache, or in a specific area?

You can see that the casualty’s injury is swollen and discoloured.  Can they tell you that it is sore to touch?  What is the pain like?  How severe?

You can see that the casualty looks pale and unhappy.  Can they tell you how they feel exactly – nauseous, cold, hot, faint?  When did this feeling start?  Have they felt like this before?


So remember that there are differences between signs and symptoms, and that they can tell us a lot as a first aider.  Often our job is to gather as much information as possible and relay it to the experts.  Writing this information down is key.  Remembering that the trend that the casualty displays over time can be extremely important.  Have a read of this blog on the acronym S.A.M.P.L.E to find out more.