有些人先天皮膚較薄，容易在鼻翼或臉頰等地方出現血管擴張，形成敏感泛紅肌膚。

Some people are born with thinner and weaker skin, which lead to vasodilatation under the skin, especially around the nose and cheeks. But there are many factors causing vasodilatation. 

Congenital factor

先天性因素

當體內荷爾蒙出現重大變化時，肌膚會變得敏感脆弱，長出微絲血管，例如孕婦在懷孕期間會出現血管擴張，在生育過後便會慢慢消失。

Our skin would react to serious hormones change, for instance, some pregnant women would suffer from vasodilatation and sensitive skin when they are pregnant but would recover after they give birth to the baby.

Hormonal factor

荷爾蒙轉變

類固醇是皮膚科的常見外塗藥物，但長期使用或用量過多會產生副作用，包括表皮萎縮變薄、微血管擴張等。

Steroid is a common external medicine used by dermatological doctors. Nonetheless, there are still some side-effects of it if it is used by patients for a long period of time or with excessive amount.

Structural Dark Eye Circles

長期／過度使用類固醇

外界因素如氣候變化會刺激到抵抗力較低的肌膚，當皮下的微絲血管變得敏感時，會較容易呈現明顯的不良反應。

Environmental factors such as sudden climate change or air pollution would irritate the skin, especially the one with weaker immunity. Veins are sensitive and would react to these external factors in a negative way.

External environmental factor

外在環境刺激

有些疾病，如糖尿病、皮膚發炎等，都有機會引發敏感泛紅的問題。

Some diseases like diabetes lead to skin sensitivity and vasodilatation.

Medical situation

疾病影響

長期處於紫外線下會令皮膚變得脆弱，令血管容易增生及變得非常顯易而見。

UV rays (UVA/UVB) cause damage to our skin and make it fragile, therefore veins under the skin would appear more obviously.

Damage of  UVA/UVB

紫外光傷害