# Systematic Review of Dyspnea and Chronic Fatigue in Patients With Long COVID: Clinical Characteristics and Associated Laboratory Parameters

## TL;DR

This paper reviews how dyspnea and chronic fatigue affect long COVID patients, highlighting the lack of consensus on their causes and the need for standardized research.

## Contribution

The study systematically synthesizes clinical and laboratory data on dyspnea and fatigue in long COVID patients from 2021 onwards.

## Key findings

- Persistent dyspnea and fatigue in long COVID patients significantly impact quality of life for up to 24 months.
- Variability in assessment methods and laboratory parameters complicates understanding of long COVID symptomatology.
- Collaborative research is urgently needed to standardize evaluation protocols and clarify underlying mechanisms.

## Abstract

Dyspnea and chronic fatigue stand out as prevalent manifestations in the postacute phase of COVID, resulting in substantial adverse effects on patients′ quality of life and functional capacity. Although these symptoms have been widely documented, there is no clear consensus on the pathophysiological mechanisms that underlie them. The available literature reveals a dispersion of clinical and laboratory data, and the variability in the methods of assessment of fatigue and dyspnea, as well as in the laboratory variables examined, limits the standardized understanding of this complex condition.

This study was aimed at identifying and synthesizing the evidence on the main clinical and laboratory characteristics related to dyspnea and fatigue in patients during long COVID from 2021 onwards.

The main databases used to select the studies were PubMed and Medline, also using LitCovid and Embase.

A total of 42 articles that met the inclusion criteria were included, covering a total population of 30,682 patients diagnosed with COVID‐19. The findings underscore the significant impact of long COVID on patients′ quality of life, with persistent symptoms such as fatigue and dyspnea affecting a considerable proportion of individuals for durations ranging from 1 to 24 months.

The heterogeneity in research approaches highlights the urgent need for collaborative initiatives to elucidate the determinants of long COVID symptomatology and create more consistent evaluation protocols.