Bilateral may refer to any concept including two sides, in particular:

Bilateria, bilateral animals
Bilateralism, the political and cultural relations between two states
Bilateral, occurring on both sides of an organism (Anatomical terms of location § Medial and lateral)
Bilateral symmetry, symmetry between two sides of an organism
Bilateral filter, an image processing algorithm
Bilateral amplifier, a type of amplifier
Bilateral (album), an album by the band Leprous
Bilateral school, see Partially selective school (England)
Superficial thrombophlebitis is a thrombosis and inflammation of superficial veins which presents as a painful induration with erythema, often in a linear or branching configuration forming cords. : 826–7 Superficial thrombophlebitis is due to inflammation and/or thrombosis, and less commonly infection of the vein. It is generally a benign, self-limited disorder, however, it can be complicated by deep vein thrombosis (DVT) and even pulmonary embolism (PE) Migratory superficial thrombophlebitis is known as Trousseaus syndrome. Signs and symptoms
Findings of tenderness, induration, pain and/or erythema along the course of a superficial vein usually establish a clinical diagnosis, especially in patients with known risk factors. In addition, there is often a palpable, sometimes nodular cord, due to thrombus within the affected vein. Persistence of this cord when the extremity is raised suggests the presence of thrombus. Complications
Superficial vein thrombosis extension to the deep vein system and/or recurrence of SVT. Suppurative thrombophlebitis is suspected when erythema extends significantly beyond the margin of the vein and is likely to be associated with significant fever. If suspected, antibiotic treatment, surgical drainage and potentially vein excision are indicated.Venous thromboembolism can occur with superficial vein thrombosis. Estimates of the percentage of patients with SVT who also have DVT vary between 6% and 53%, and symptomatic pulmonary embolism has been reported in 0% to 10% of patients with SVT. Risk factors
Patient characteristics and predisposing factors for thrombophlebitis nearly mirror those for DVT; thrombophlebitis is a risk factor for the development of DVT, and vice versa.