What Happens Beneath a Cupping Cup?

Creating Negative Pressure

A cupping vessel works by evacuating air from a sealed chamber placed against the skin, creating a region of negative pressure that pulls the skin, superficial fascia and underlying soft tissue upward into the cup. Biomechanical modelling of this process shows the resulting tissue displacement and shear is substantial relative to normal physiological loading, concentrated most heavily at the skin and superficial fascial layers directly beneath the cup rim (Tham et al., 2006).

What Happens to the Blood Vessels

This negative pressure dilates local capillaries and venules and, depending on the suction level and duration, can rupture the smallest and most superficial vessels, producing the characteristic circular marking through capillary extravasation — a visible and measurable local increase in blood flow that persists for some time after the cup is removed (Al-Bedah et al., 2019).

Fluid Dynamics and Mechanoreceptor Stimulation

Beyond the vascular response, the sustained stretch applied to skin and superficial fascia is thought to shift local interstitial fluid dynamics and stimulate cutaneous mechanoreceptors, contributing to the same kind of descending pain-modulatory response implicated in other forms of manual therapy. Where the cup is moved across the skin during treatment (dynamic or "sliding" cupping), an additional myofascial gliding component is introduced, broadly comparable in principle to instrument-assisted soft tissue mobilisation.