When you hit your head in a slip or fall, you can suffer a traumatic brain injury (TBI). TBIs are divided into two broad categories - open head injuries, which are injuries where the skull is penetrated, and closed head injuries, which are injuries where the skull is not opened. As you can imagine, an open head injury has obvious symptoms.
When you use a consumer product, it is your responsibility to ensure that it is safe for you to use. Many of the food allergens that can cause uncomfortable and harmful reactions can also be found in non-food products. Although you do not eat these products, you can still suffer an allergic reaction just by coming into contact with them.