What are flu-like characteristics?
Flu-like symptoms are a group of symptoms that are generally due to infection or inflammation in the body. There are a variety of flu-like symptoms that include:
- Body aches and pains
- Muscle soreness
- Nasal congestion
- Sore throat
You may experience all or some of these symptoms, and you can have flu-like symptoms with or without a fever. A fever is considered an oral temperature of 99.5 degrees or higher in a child and higher than 99.0 to 99.5 degrees in an adult.
Flu-like symptoms can be associated not only with influenza (flu), but with other infections, recent immunization, autoimmune and inflammatory disorders, cancer, and other conditions, including serious or life-threatening infections.
If your flu-like symptoms or fever last for more than 48 hours or cause you concern, seek prompt medical care. Fever in infants and very young children can quickly become serious, so you should seek prompt medical care if your baby or toddler develops a fever.
Seek immediate medical care (call 911) if you, or someone you are with, have flu-like symptoms that occur with difficulty breathing, stiff neck, seizure, confusion, or a change in alertness.
What other symptoms might occur with flu-like symptoms?
Flu-like symptoms may occur with other symptoms depending on the underlying disease, disorder or condition. Flu-like symptoms usually indicate an infection or inflammation in the body, which can cause additional symptoms, such as:
- Cold, clammy skin
- Flushed face
- General ill feeling (malaise)
- Hot, dry skin
- Joint pain
- Loss of appetite
- Nausea and vomiting
Serious symptoms that might indicate a life-threatening condition
In some cases, flu-like symptoms may occur with other symptoms that can indicate a serious or life-threatening condition. Seek immediate medical care (call 911) if you, or someone you are with, have flu-like symptoms with any of the following symptoms:
- Abnormal pupil size and reactivity to light
- Bleeding symptoms, such as vomiting blood, bloody urine, bloody stool,or major rectal bleeding
- Change in level of consciousness or alertness, such as passing out or unresponsiveness
- Change in mental status or sudden behavior change, such as confusion, delirium, lethargy, hallucinations and delusions
- Chest pain, chest tightness, chest pressure, palpitations
- High fever (higher than 101 degrees Fahrenheit)
- Not producing any urine, or an infant who does not produce the usual amount of wet diapers
- Pale or bluish coloration (cyanosis)
- Paralysis of any part of the body
- Productive cough with yellow-green or blood-tinged mucus
- Respiratory or breathing problems, such as shortness of breath, difficulty breathing, labored breathing, wheezing, not breathing, or choking
- Severe headache
- Stiff neck, possibly with a rash, nausea and vomiting, or confusion
- Swelling or edema, including swollen lymph nodes
- Vision loss
What causes flu-like symptoms?
Many types of infections, inflammatory disorders, and other conditions can cause flu-like symptoms. Common infections include flu (influenza), pneumonia, appendicitis, and urinary tract infections. Symptoms of rheumatoid arthritis and other connective tissue conditions can include flu-like symptoms. There are many possible causes of flu-like symptoms, so talk with your medical professional about your symptoms.
Infectious causes of flu-like symptoms
Flu-like symptoms are associated with many different types of infections:
- Common cold (viral respiratory infection)
- Lyme disease
- Malaria (international travel)
- Meningitis (infection or inflammation of the sac around the brain and spinal cord)
- Rocky Mounted Spotted Fever
- Septic arthritis (infectious arthritis)
- Sexually transmitted diseases, such as genital herpes and HIV/AIDS
- Tuberculosis (serious infection affecting the lungs and other organs)
- Urinary tract infection
- West Nile virus
Other causes of flu-like symptoms
Flu-like symptoms can also be caused by inflammatory conditions and other abnormal processes including:
- Blood transfusion
- Cancer, such as leukemia or lymphoma
- Chronic fatigue syndrome
- Electrolyte disturbances (potassium, calcium, magnesium)
- Inflammatory bowel disease (includes Crohn’s disease and ulcerative colitis)
- Polymyalgia rheumatica
- Rheumatoid arthritis (chronic autoimmune disease characterized by joint inflammation)
- Systemic lupus erythematosus (disorder in which the body attacks its own healthy cells and tissues)
How is the cause of flu-like symptoms diagnosed?
To diagnose the underlying cause of flu-like symptoms, your doctor or licensed health care practitioner will ask you several questions related to your symptoms. You can best help your health care practitioner in diagnosing the underlying cause of flu-like symptoms by providing complete answers to these questions:
- What symptoms are you experiencing?
- When did your symptoms start?
- Where have you traveled recently?
- Have you had a fever? If so, how high was the fever?
- Have you had any trouble breathing, neck pain or stiffness, or bleeding?
What are potential complications of flu-like symptoms?
Complications associated with flu-like symptoms can be progressive and vary depending on the underlying cause. In some cases, flu-like symptoms can be caused by serious diseases, such as meningitis, that can rapidly result in life-threatening complications.
It is important to contact your health care provider promptly when you experience flu-like symptoms. Once the underlying cause is diagnosed, following the treatment plan that you and your health care provider design specifically for you can help reduce any potential complications including:
- Absenteeism from work or school
- Dehydration due to accompanying diarrhea or vomiting, reduced fluid intake, fever, or increased sweating
- Inability to perform daily tasks
- Poor quality of life
- Pregnancy complications, such as miscarriage, birth defects, and serious newborn infections
- Shock, coma, and organ failure
- Sleep disturbance