This study aims to retrospectively examine the dataset obtained from a previously conducted study titled 'Inspiratory muscle training in individuals with chronic venous insufficiency: randomized controlled trial'. The previously conducted study was a study investigating the effectiveness of the application, and the current study aims to clarify the gap in the literature with the relationship between the data obtained from the patients at the beginning of that study. This study will be conducted by re-examining the initial data of another study from which data was collected before and conducting new analyses.

H0: There is no relationship between disease severity, edema, pain, respiratory muscle strength, respiratory functions, aerobic capacity, lower extremity strength or quality of life in individuals with chronic venous insufficiency.

H1: There is a relationship between disease severity, edema, pain, respiratory muscle strength, respiratory functions, aerobic capacity, lower extremity strength or quality of life in individuals with chronic venous insufficiency.

Chronic Venous Insufficiency (CVI) is a term used to describe a disorder that affects the venous system of the lower extremities and results in venous hypertension. Venous pathology develops when venous pressure increases and the return of blood is impaired by various mechanisms. These pathologies are caused by valve insufficiency, venous obstruction or inadequate functioning of the muscle pump. The veins in the calf and the tissues surrounding them form the muscle pump. The muscle pump is responsible for venous blood circulation and is activated by ankle movements. In venous insufficiency, one-way valves and vein walls relax, resulting in muscle pump dysfunction. CVI can cause various pathologies and subjective symptoms such as leg pain and cramps, a feeling of heaviness, edema and skin changes. All these symptoms negatively affect the quality of life depending on the intensity of pain, severity of edema and the presence of inflammation. In CVI, the limitation of ankle movement is one of the factors that increase edema and venous severity. Fibrotic tissue formations in the lower extremity cause limitation in ankle movements. It should not be forgotten that functionality and quality of life are closely related phenomena, as the physical activity levels and functional capacity deterioration of people with chronic venous insufficiency increase, the quality of life decreases, which further worsens the prognosis of the disease. Complications of CVI impair the person's ability to participate in social or routine occupational activities, reduce working capacity, and ultimately increase the economic burden on the person and the family. Chronic venous diseases are a common condition that causes great socioeconomic effects due to their high prevalence. 32% of women and 40% of men have varicose veins. In addition, any type of venous disease affects 40-50% of men and 50-55% of women. CVI risk factors include heredity, pregnancy, aging, thrombosis, connective tissue laxity, inactivity, excessive weight, use of high-heeled shoes, standing for long periods, wearing tight clothes, being a woman, geographical effects and improper eating habits. Diagnosis of chronic venous disease is based on anamnesis, clinical symptoms and diagnostic tests. Today, duplex ultrasound is the gold standard for the diagnosis of CVI. The most widely used classification system for the classification of CVI is the CEAP classification system, which includes clinical, etiological, anatomical and pathophysiological effects and stages. In this classification, CEAP stands for; C: Clinical appearance, E: Etiological factors, A: Anatomical distribution, P: Pathophysiological condition. In general, C (clinical features)-classification is used in daily clinical practice. Insufficiency of the muscle pump includes not only calf muscle insufficiency but also respiratory muscle insufficiency. The diaphragm is a dome-shaped musculofibrous layer that separates the thorax and abdomen. The diaphragm, which acts as the main inspiratory muscle, creates a suction effect on the inferior vena cava during inspiration and expiration, allowing more blood flow from the lower extremities to the heart. Changes in pressure in the thoraco-abdominal region directly affect venous flow. Inspiration increases negative intrathoracic pressure, causing blood to be sucked into the thorax. Simultaneously, the diaphragm contracts and the abdominal veins are compressed. These changes in intrathoracic and intraabdominal pressures that occur with respiration help venous return by preventing retrograde flow in the veins. It has been shown that the respiratory cycle affects venous return in healthy individuals, and that the flow rate in the femoral vein increases with deep inspiration. However, no study has been found examining the relationship between disease severity, edema, pain, respiratory muscle strength, respiratory functions, aerobic capacity, lower extremity strength and quality of life in individuals with chronic venous insufficiency. For this reason, since the relationship between disease severity, disease symptoms, respiratory functions, aerobic capacity and quality of life in individuals with chronic venous insufficiency is unknown, this study aimed to clarify it.

Inclusion Criteria:

• Being diagnosed with chronic venous insufficiency
• Agreeing to participate in the study
• Being 18 years of age or older

Exclusion Criteria:

• Presence of arterial diseases
• Presence of advanced cardiorespiratory diseases
• Presence of acute ulcers (< 3 months) and diabetic ulcers
• Being pregnant
• Presence of deep vein thrombosis
• Presence of active infection

Individuals diagnosed with chronic venous insufficiency volunteered to participate in the study