"Severe symptoms" refers to signs or effects of a condition or illness that are serious or intense, causing significant discomfort or harm to a person's health. Full definition
Trouble breathing is one of the more severe symptoms of an egg allergy and one that requires your immediate attention. (earlymomentsmatter.org)
Overall, the results suggest children of parents with ADHD have more severe symptoms of the disorder compared to children without an affected parent. (link.springer.com)
They enrolled 152 children with autism, many of them with severe symptoms of the disorder. (scientificamerican.com)