深静脉是在骨骼旁边的肌肉中发现的静脉。它们阻止血液从心脏向后流动，并帮助推动血液向前流向心脏(Arya et al.， 2002)。深静脉血栓(Deep vein thrombosis, DVT)是一种发生在深静脉的血块。这通常是一种非常不舒服的情况，伴随着小腿肌肉的肿胀。当血栓进入肺部并引起肺栓塞时，可能危及生命。长途航空旅行被认为是造成深静脉血栓的原因之一。这一分析的目的是探讨这种疾病的生理过程、危险因素和治疗方法。
肌肉静脉可将血液排入下肢深静脉。血栓形成发展为静脉停滞。静脉淤血是一种导致静脉瓣膜窦周围血流减少的情况。这会导致血栓的形成。形成的血栓在临床上可引起静脉阻塞导致的瓣膜损伤和血栓栓塞情况，即血栓(Kelman et al.， 2003)。发生这种情况的危险因素在下一节中讨论。
在长途旅行中长时间坐着不动会导致一些旅行者易患深静脉血栓。DVT甚至被戏称为“经济舱综合征”。由于经济舱的腿部空间有限，但如果乘客坐的时间较长，任何一种旅行都可能出现这种情况。有些旅行者喜欢长时间坐着，不锻炼腿，容易患这种病。没有收缩和挤压的肌肉导致腿部静脉不供血(Schwarz et al.， 2003)。
旅行时穿有紧弹性的袜子会使静脉收缩。如果旅行者不动或不锻炼他们的腿，这种情况会恶化(Schwarz et al.， 2003)。
Deep veins are the veins that are found in muscles alongside the bones. They prevent blood to flow backwards from the heart and helps in propelling the blood forward towards the heart (Arya et al., 2002). Deep vein thrombosis (DVT) is a condition where there is blood clot that develops in deep veins. This is generally a very uncomfortable condition along with swelling of the calf muscles. This clot can be life threatening when it travels to the lungs and cause pulmonary embolism. Long-haul air travel has been considered to be one of the causes for DVT. The purpose of this analysis is to look into the physiological process, risk factors and treatment of the condition.
Anatomical and physiological process of DVT
Muscle veins are found to drain blood into deep veins of lower extremity. Thrombosis develops as venous stasis. Venous stasis is the condition that causes the blood flow to be reduced around the venous valve sinuses. This leads to the formation of clots. Clots that are formed are found to clinically cause damage to valves due to venous obstruction and cause thromboembolism condition i.e. blood clots (Kelman et al., 2003). The risk factors for developing the condition have been discussed in the following section.
The risk factors of develop DVT during airline travel are:
Sitting motionless for long periods during long travel can cause some travellers to become susceptible to DVT. DVT has been even nicknamed as “economy class syndrome”. Owing to the fact that the leg space is limited in the economy class, but it can occur in any class of travel, if the passenger sits for longer duration. Some travellers prefer to sit for long periods of time and do not exercise their leg are susceptible to develop this condition. The muscles that are not contracted and squeezed causes the leg veins to not pump blood (Schwarz et al., 2003).
This is found to be worse in the case of adults. Children under the age of 5 tend to move their legs and exercise their legs a lot in their seats. Owing to this, the risk factor is reduced.
Wearing socks with tight elastic during travel can constrict the veins during travel. This condition worsens if the travellers do not move or exercise their legs (Schwarz et al., 2003).
Dehydration during travel causes the blood vessels to become narrow and the blood to thicken. Increased alcohol and coffee consumption during travel contribute towards development of this disease. This has not been scientifically proven, but has been considered as a common sense approach to understand about DVT.