Being sick can cause headaches, as many illnesses directly or indirectly trigger this common symptom. Conditions such as colds, the flu, sinus infections, and even dehydration from illness can lead to headaches. These headaches often result from inflammation, congestion, or fever accompanying infections. Additionally, the body's immune response to fighting off illness can also contribute to headaches. Understanding the underlying illness is key to managing headaches effectively during sickness. If you’re suffering from ...