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.

Temperature varies a little depending on how you measure it. For adults and children age 12 and older, these are the ranges for high, moderate, and mild, according to how you took the temperature.

Oral (by mouth) 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.

Ear temperature

• High: 105°F (40.6°C) and higher
• Moderate: 101.4°F (38.6°C) to 104.9°F (40.5°C)
• Mild: 101.3°F (38.5°C) and lower

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

Symptoms of an external ear infection may include:

• Moderate to severe pain in the outer ear.
• Pain with chewing.
• Redness and swelling of the ear, ear canal, or the skin around or behind the ear.

Vertigo is the feeling that you or your surroundings are moving when there is no actual movement. It may feel like spinning, whirling, or tilting. Vertigo may make you sick to your stomach, and you may have trouble standing, walking, or keeping your balance.

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.

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

With a high fever:

• You feel very hot.
• It is likely one of the highest fevers you've ever had. High fevers are not that common, especially in adults.

With a moderate fever:

• You feel warm or hot.
• You know you have a fever.

With a mild fever:

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

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.

Symptoms of a stroke may include:

• Sudden numbness, tingling, weakness, or paralysis in your face, arm, or leg, especially on only one side of your body.
• Sudden vision changes.
• Sudden trouble speaking.
• Sudden confusion or trouble understanding simple statements.
• Sudden problems with walking or balance.
• A sudden, severe headache that is different from past headaches.