A new study has classified long COVID into five distinct types, helping doctors better understand and treat the condition. Researchers from the United States National Institutes of Health’s RECOVER COVID Initiative analysed data from 14,000 long COVID patients and an additional 4,000 individuals to develop this classification system, Medscape reported on 20 February 2025.
Long COVID is difficult to diagnose and treat due to its wide range of symptoms. This new index allows doctors to identify which symptoms are most common and provide more targeted care. It also opens the door for further research into potential treatments.
Understanding the Five Subtypes of Long COVID
Researchers assigned 44 commonly reported symptoms into five categories based on their severity and impact on quality of life.
Subtype 1
- Mildest form, with minimal impact on daily life.
- 100% of patients reported a loss of smell or taste.
- Other common symptoms: fatigue (66%), post-exertional malaise (53%), and soreness (55%).
Subtype 2
- More severe, with increased fatigue (81%) and chronic cough (100%).
- 25% reported poor or fair quality of life.
- Includes post-exertional malaise, a symptom linked to chronic fatigue syndrome
Subtype 3
- Significant impact on daily life, with 37% reporting poor or fair quality of life.
- Symptoms include fatigue (92%), dizziness (70%), and brain fog (100%).
- Linked to postural orthostatic tachycardia syndrome, which causes heart palpitations and fainting.
Subtype 4
- More severe symptoms, with 40% reporting poor or fair quality of life.
- Includes brain fog (65%), dizziness (71%), and gastrointestinal issues (60%).
Subtype 5
- Most severe form, with 66% reporting poor to fair quality of life.
- Symptoms affect multiple body systems, including shortness of breath (99%), post-exertional soreness (98%), dizziness (94%), and chest pain (69%).
- More common in unvaccinated individuals and those infected before the Omicron variant.
Long COVID Recovery Outlook
Around 17 million Americans are estimated to have long COVID. While most recover within three years, about 5% continue to struggle with symptoms. Experts emphasise the importance of identifying symptoms early and providing personalised treatment to improve patients’ quality of life.