Many things can affect how your body responds to a symptom and what kind of care you may need. These include:

• Your age. Babies and older adults tend to get sicker quicker.
• Your overall health. If you have a condition such as diabetes, HIV, cancer, or heart disease, you may need to pay closer attention to certain symptoms and seek care sooner.
• Medicines you take. Certain medicines, such as blood thinners (anticoagulants), medicines that suppress the immune system like steroids or chemotherapy, or natural health products can cause symptoms or make them worse.
• Recent health events, such as surgery or injury. These kinds of events can cause symptoms afterwards or make them more serious.
• Your health habits and lifestyle, such as eating and exercise habits, smoking, alcohol or drug use, sexual history, and travel.

Pain in adults and older children

• Severe pain (8 to 10): The pain is so bad that you can't stand it for more than a few hours, can't sleep, and can't do anything else except focus on the pain.
• Moderate pain (5 to 7): The pain is bad enough to disrupt your normal activities and your sleep, but you can tolerate it for hours or days. Moderate can also mean pain that comes and goes even if it's severe when it's there.
• Mild pain (1 to 4): You notice the pain, but it is not bad enough to disrupt your sleep or activities.

Pain in children under 3 years

It can be hard to tell how much pain a baby or toddler is in.

• Severe pain (8 to 10): The pain is so bad that the baby cannot sleep, cannot get comfortable, and cries constantly no matter what you do. The baby may kick, make fists, or grimace.
• Moderate pain (5 to 7): The baby is very fussy, clings to you a lot, and may have trouble sleeping but responds when you try to comfort him or her.
• Mild pain (1 to 4): The baby is a little fussy and clings to you a little but responds when you try to comfort him or her.

Symptoms of infection may include:

• Increased pain, swelling, warmth, or redness in or around the area.
• Red streaks leading from the area.
• Pus draining from the area.
• A fever.

Symptoms of difficulty breathing can range from mild to severe. For example:

• You may feel a little out of breath but still be able to talk (mild difficulty breathing), or you may be so out of breath that you cannot talk at all (severe difficulty breathing).
• It may be getting hard to breathe with activity (mild difficulty breathing), or you may have to work very hard to breathe even when you're at rest (severe difficulty breathing).

Symptoms of a severe allergic reaction can start within minutes of eating or being exposed to an allergen. While symptoms usually occur within 2 hours, in rare cases the time frame can vary up to several hours after exposure. Do not ignore early symptoms. When a reaction begins, it is important to respond right away.

• Skin: hives, swelling (face, lips, tongue), itching, warmth, redness
• Respiratory (breathing): coughing, wheezing, shortness of breath, chest pain or tightness, throat tightness, hoarse voice, nasal congestion or hay fever-like symptoms (runny, itchy nose and watery eyes, sneezing), trouble swallowing
• Gastrointestinal (stomach): nausea, pain or cramps, vomiting, diarrhea
• Cardiovascular (heart): paler than normal skin colour/blue colour, weak pulse, passing out, dizziness or lightheadedness, shock
• Other: anxiety, sense of doom (the feeling that something bad is about to happen), headache, uterine cramps, metallic taste

A severe reaction can take place without hives, so make sure to look out for all of the signs of an allergic reaction.

Certain health conditions and medicines weaken the immune system's ability to fight off infection and illness. Some examples in adults are:

• Diseases such as diabetes, cancer, heart disease, and HIV/AIDS.
• Long-term alcohol and drug problems.
• Steroid medicines, which may be used to treat a variety of conditions.
• Chemotherapy and radiation therapy for cancer.
• Other medicines used to treat autoimmune disease.
• Medicines taken after organ transplant.
• Not having a spleen.

You may need a tetanus shot depending on how dirty the wound is and how long it has been since your last shot.

• For a deep or dirty wound that has things like dirt, saliva, or feces in it, you may need a shot if:
  • You haven't had a tetanus shot in the past 5 years.
  • You don't know when your last shot was.
  • You have not received 3 doses of the tetanus vaccine series.
• For a clean wound, you may need a shot if:
  • You have not had a tetanus shot in the past 10 years.
  • You don't know when your last shot was.
  • You have not received 3 doses of the tetanus vaccine series.

Shock is a life-threatening condition that may quickly occur after a sudden illness or injury.

Adults and older children often have several symptoms of shock. These include:

• Passing out (losing consciousness).
• Feeling very dizzy or light-headed, like you may pass out.
• Feeling very weak or having trouble standing.
• Not feeling alert or able to think clearly. You may be confused, restless, fearful, or unable to respond to questions.

Shock is a life-threatening condition that may occur quickly after a sudden illness or injury.

Babies and young children often have several symptoms of shock. These include:

• Passing out (losing consciousness).
• Being very sleepy or hard to wake up.
• Not responding when being touched or talked to.
• Breathing much faster than usual.
• Acting confused. The child may not know where he or she is.