Stress can indeed contribute to fluid retention and ankle swelling, although the relationship is complex and involves multiple physiological mechanisms. When the body experiences stress, it triggers a cascade of hormonal responses that can affect fluid balance and circulation, potentially leading to swelling, especially in the lower extremities.
One key hormone involved in the stress response is cortisol, often called the “stress hormone.” Elevated cortisol levels, which occur during stress, have mineralocorticoid effects similar to aldosterone, meaning they can promote sodium retention by the kidneys. Sodium retention leads to water retention because water follows sodium to maintain osmotic balance. This process can increase blood volume and cause fluid to accumulate in tissues, manifesting as swelling or edema, particularly in gravity-dependent areas like the ankles[4].
Additionally, stress activates the hypothalamic-pituitary-adrenal (HPA) axis and the sympathetic nervous system, which can increase the release of vasopressin (also known as antidiuretic hormone). Vasopressin acts on the kidneys to conserve water, reducing urine output and promoting fluid retention. This hormone is part of the body’s effort to maintain blood pressure and volume during stress but can contribute to edema if elevated chronically[1].
Poor hydration status can exacerbate this effect. Research shows that individuals who are under-hydrated have higher cortisol responses to stress, which may amplify fluid retention mechanisms. Dehydration triggers vasopressin release to conserve water, and combined with stress-induced cortisol elevation, this can increase the risk of fluid buildup[1].
Stress also influences the cardiovascular system by causing blood vessels to constrict or dilate irregularly, which can impair normal circulation. Poor circulation in the legs can cause fluid to pool in the tissues, leading to swelling. Moreover, stress can promote inflammation, which increases capillary permeability, allowing fluid to leak into surrounding tissues more easily[2].
While stress alone can contribute to fluid retention and ankle swelling, it is often one factor among many. Other causes include dietary salt intake, physical inactivity, hormonal fluctuations, certain medications, and underlying medical conditions such as heart, kidney, or liver disease. However, the hormonal and physiological changes induced by stress are significant contributors to these symptoms in many cases.
In summary, stress causes the release of hormones like cortisol and vasopressin that promote sodium and water retention by the kidneys. This hormonal activity, combined with effects on blood vessel function and inflammation, can lead to fluid accumulation and swelling in the ankles. Maintaining good hydration and managing stress levels may help reduce these symptoms.
Sources:
[1] ScienceDaily, “How dehydration secretly fuels anxiety and health problems,” 2025
[2] AJMC, “5 Ways Anxiety Can Affect Gut Health,” 2025
[4] DrOracle.ai, “Fluid Intake Recommendations for Patients with Hypercortisolism,” 2025
