Inclusion Criteria:  Men and women at least 40 years old, able and willing to give informed consent; Ambulatory or hospitalized environment; Patient with dyspnea or with a positive gait test; The patient must have at least one of the following high risk criteria: 70 years or older, obesity (BMI ≥ 30 kg / m2), diabetes mellitus, uncontrolled hypertension (systolic blood pressure ≥ 150 mm Hg), respiratory disease known (including asthma or chronic obstructive pulmonary disease), known heart failure, known coronary artery disease, fever ≥ 38.4 ° C within the last 48 hours, dyspnea at the time of presentation, bicytopenia, pancytopenia or a combination of a number high neutrophils and low lymphocytes count; The patient is not of childbearing age, defined as postmenopausal for at least 1 year or surgically sterile, or is of childbearing age and uses at least one method of contraception and preferably two complementary forms of contraception comprising a method of barrier throughout the study and for 30 days after the end of the study; The patient must be able and willing to comply with the requirements of this study protocol.  Exclusion Criteria:  Patient currently in shock or exhibiting hemodynamic instability; Patient with inflammatory bowel disease (Crohn's disease or ulcerative colitis), chronic diarrhea or malabsorption; Pregnant or breastfeeding patient Patient with a history of allergic reaction or significant sensitivity to Nigella; The patient is considered by the investigator, for whatever reason, to be an unsuitable candidate for the study.  Given the non-homogeneity of the patients, the study population will be divided into two groups:  group of outpatients: Ambulatory patients and inpatient group: Hospitalised patients Statistical analysis will be carried out for each group separately