How is tissue fluid absorbed into blood capillaries?
In general tissue fluid will leave the tissue by entering the lymphatics which drain into the blood circulation at the thoracic duct beside the subclavian vein in your chest. There is some return at the end of the capillaries due to osmotic pressure. As fluid leaves the capillaries it leaves the blood slightly concentrated and so there is some re-entry of fluid through the endothelial cells which as other folk have said by diffusion until the system balances.
