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, herbal remedies, or supplements 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.

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 difficulty breathing in a baby or young child can range from mild to severe. For example:

• The child may be breathing a little faster than usual (mild difficulty breathing), or the child may be having so much trouble that the nostrils are flaring and the belly is moving in and out with every breath (severe difficulty breathing).
• The child may seem a little out of breath but is still able to eat or talk (mild difficulty breathing), or the child may be breathing so hard that he or she cannot eat or talk (severe difficulty breathing).

Severe trouble breathing means:

• The child cannot eat or talk because he or she is breathing so hard.
• The child's nostrils are flaring and the belly is moving in and out with every breath.
• The child seems to be tiring out.
• The child seems very sleepy or confused.

Moderate trouble breathing means:

• The child is breathing a lot faster than usual.
• The child has to take breaks from eating or talking to breathe.
• The nostrils flare or the belly moves in and out at times when the child breathes.

Mild trouble breathing means:

• The child is breathing a little faster than usual.
• The child seems a little out of breath but can still eat or talk.

You can use a small rubber bulb (called an aspirating bulb) to remove mucus from your baby's nose or mouth when a cold or allergies make it hard for the baby to eat, sleep, or breathe.

To use the bulb:

1. Put a few saline nose drops in each side of the baby's nose before you start.
2. Position the baby with his or her head tilted slightly back.
3. Squeeze the round base of the bulb.
4. Gently insert the tip of the bulb tightly inside the baby's nose.
5. Release the bulb to remove (suction) mucus from the nose.

Don't do this more than 5 or 6 times a day. Doing it too often can make the congestion worse and can also cause the lining of the nose to swell or bleed.

If you're not sure if a child's fever is high, moderate, or mild, think about these issues:

With a high fever:

• The child feels very hot.
• It is likely one of the highest fevers the child has ever had.

With a moderate fever:

• The child feels warm or hot.
• You are sure the child has a fever.

With a mild fever:

• The child may feel a little warm.
• You think the child might have a fever, but you're not sure.

A baby that is extremely sick:

• May be limp and floppy like a rag doll.
• May not respond at all to being held, touched, or talked to.
• May be hard to wake up.

A baby that is sick (but not extremely sick):

• May be sleepier than usual.
• May not eat or drink as much as usual.

Temperature varies a little depending on how you measure it. For children up to 11 years old, here are the ranges for high, moderate, and mild according to how you took the temperature.

Oral (by mouth), ear, or rectal temperature

• High: 104° F (40° C) and higher
• Moderate: 100.4° F (38° C) to 103.9° F (39.9° C)
• Mild: 100.3° F (37.9° C) and lower

A forehead (temporal) scanner is usually 0.5° F (0.3° C) to 1° F (0.6° C) lower than an oral temperature.

Armpit (axillary) temperature

• High: 103° F (39.5° C) and higher
• Moderate: 99.4° F (37.4° C) to 102.9° F (39.4° C)
• Mild: 99.3° F (37.3° C) and lower

Note: For children under 5 years old, rectal temperatures are the most accurate.

Symptoms of serious illness in a baby may include the following:

• The baby is limp and floppy like a rag doll.
• The baby doesn't respond at all to being held, touched, or talked to.
• The baby is hard to wake up.

Symptoms of serious illness may include:

• A severe headache.
• A stiff neck.
• Mental changes, such as feeling confused or much less alert.
• Extreme fatigue (to the point where it's hard for you to function).
• Shaking chills.

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

• Diseases such as diabetes, cystic fibrosis, sickle cell disease, and congenital heart disease.
• Steroid medicines, which are used to treat a variety of conditions.
• Medicines taken after organ transplant.
• Chemotherapy and radiation therapy for cancer.
• Not having a spleen.

Sudden drooling and trouble swallowing can be signs of a serious problem called epiglottitis. This problem can happen at any age.

The epiglottis is a flap of tissue at the back of the throat that you can't see when you look in the mouth. When you swallow, it closes to keep food and fluids out of the tube (trachea) that leads to the lungs. If the epiglottis becomes inflamed or infected, it can swell and quickly block the airway. This makes it very hard to breathe.

The symptoms start suddenly. A person with epiglottitis is likely to seem very sick, have a fever, drool, and have trouble breathing, swallowing, and making sounds. In the case of a child, you may notice the child trying to sit up and lean forward with his or her jaw forward, because it's easier to breathe in this position.