The article discusses the diagnosis of ischaemic heart pain and intermittent claudication in field surveys. It emphasizes the need for precise definitions and standardized questionnaires to distinguish these conditions from other causes of chest or leg pain. The study uses hospital data to identify key characteristics of angina pectoris, cardiac infarction, and intermittent claudication. These characteristics are used to formulate definitions for epidemiological use and to develop a standardized questionnaire. The questionnaire was found to have high specificity and reasonable sensitivity compared to physicians' diagnoses. However, interpreting answers can be challenging, especially in populations with high prevalence of chronic bronchitis. The study highlights the differences between the needs of clinicians and epidemiologists. Clinicians seek broad definitions to cover various forms of a disease, while epidemiologists require clear, standardized definitions for accurate and comparable data collection. The WHO definition of angina pectoris is discussed, but it is noted that it is too general for precise diagnostic criteria. The study proposes specific definitions for angina pectoris, possible cardiac infarction, and intermittent claudication based on characteristics such as the site of pain, provocation by exertion, response to rest, and duration of pain. These definitions are intended for use in epidemiological studies. The study also discusses the use of electrocardiography in diagnosing ischaemic heart disease, noting its limitations in detecting all cases. The proposed questionnaire is designed to identify cases of angina, possible infarction, and intermittent claudication. It has been validated through various studies, showing high sensitivity and specificity. However, it is noted that in populations with high prevalence of chronic bronchitis, the diagnosis of angina may be problematic. The article concludes that standardized questionnaires are essential for international comparisons of disease prevalence and that further research is needed to refine diagnostic criteria and techniques.The article discusses the diagnosis of ischaemic heart pain and intermittent claudication in field surveys. It emphasizes the need for precise definitions and standardized questionnaires to distinguish these conditions from other causes of chest or leg pain. The study uses hospital data to identify key characteristics of angina pectoris, cardiac infarction, and intermittent claudication. These characteristics are used to formulate definitions for epidemiological use and to develop a standardized questionnaire. The questionnaire was found to have high specificity and reasonable sensitivity compared to physicians' diagnoses. However, interpreting answers can be challenging, especially in populations with high prevalence of chronic bronchitis. The study highlights the differences between the needs of clinicians and epidemiologists. Clinicians seek broad definitions to cover various forms of a disease, while epidemiologists require clear, standardized definitions for accurate and comparable data collection. The WHO definition of angina pectoris is discussed, but it is noted that it is too general for precise diagnostic criteria. The study proposes specific definitions for angina pectoris, possible cardiac infarction, and intermittent claudication based on characteristics such as the site of pain, provocation by exertion, response to rest, and duration of pain. These definitions are intended for use in epidemiological studies. The study also discusses the use of electrocardiography in diagnosing ischaemic heart disease, noting its limitations in detecting all cases. The proposed questionnaire is designed to identify cases of angina, possible infarction, and intermittent claudication. It has been validated through various studies, showing high sensitivity and specificity. However, it is noted that in populations with high prevalence of chronic bronchitis, the diagnosis of angina may be problematic. The article concludes that standardized questionnaires are essential for international comparisons of disease prevalence and that further research is needed to refine diagnostic criteria and techniques.