Who's Most At Risk? Understanding Severe Flu Risk Factors

Flu cases have started to rise as temperatures drops. Flu or influenza is a contagious viral infection that targets the respiratory system of a person. Key symptoms include fever, chills, cough, sore throat, stuffy nose, body aches, headaches amongst others. Government statistics show that this infection causes 710,000 hospitalizations and 51,000 deaths annually in US.

While for many, the immune system clears the symptoms in about a week, for others, it can lead to severe illness, hospitalization, or even death. A new analysis by the Centers for Disease Control and Prevention (CDC), which examined flu-related hospitalizations from 2010 to 2023, reveals some of the factors that put people most at risk of severe health outcomes.

Age plays a crucial role when it comes to immunity. As a result, young children and older adults are consistently hospitalized with the flu at the highest rates, as their bodies find it tough to fend off infections compared to healthy adults.

People with neurological disorders are also at higher risk, especially children. Conditions like epilepsy, cerebral palsy, and ADHD can impair muscle and lung function, making it harder for individuals to cough or clear fluids from their respiratory tracts. This can severely exacerbate flu symptoms or lead to pneumonia.

Flu can also trigger asthma attacks in children with lung diseases. By causing chronic inflammation of the airways, it can lead to pneumonia and other severe illnesses that require hospitalization.

Meanwhile, adults with chronic obstructive pulmonary disease (COPD) find it harder to clear a bout of flu, due to weakened immune response.

Moreover, research shows that pregnancy hormones weaken the immune system, increasing the risk of severe infections and hospitalizations. According to the CDC, nearly 30% of women of reproductive age who were hospitalized with the flu over 13 flu seasons were pregnant. Notably, contracting the flu while pregnant also poses risks to the fetus.

Obesity is another risk factor for severe illness from the flu in both children and adults. Excess weight can make it harder to take deep breaths needed to clear an infection from the lungs. Obesity is also linked with other metabolic diseases like diabetes and hypertension. In patients with diabetes, a bout of flu can make blood sugar levels harder to control.

According to the CDC, about half of adults hospitalized with the flu have heart disease, which weakens the immune system. Additionally, the flu itself increases the risk of heart attack and stroke in people already suffering from cardiovascular disease.

Flu vaccines have been shown to significantly reduce the risk of hospitalization for both children and adults. A recent study revealed that vaccination decreased the hospitalization rate by 34.5% this year across five South American countries, where flu season arrives earlier. However, experts stress that even if you are vaccinated, it’s important to watch for symptoms that might require medical attention, such as difficulty breathing and chest pain.