He is under the weather.

他不舒服，生病了

She has been shut-in for a few days.

她生病在家几天了。

He began to feel unusually tired.

他感到反常的疲倦

He feels exhausted/fatigued most of the time.

他大部份时间都觉得非常疲倦。

He has been lacking in energy for some time.

他感到虚弱有段时间了。

He feels light-headed.

他觉得头晕。

Her head is pounding.

她头痛。

He feels as though everything around him is spinning.

他感到周围的东西都在打转。

He has noticed some loss of hearing.

他发觉听力差些。

She has some pains and itching around her eyes.

她眼睛四周又痛又痒。

He feels drowsy, dizzy and nauseated.

他觉得昏昏欲睡，头晕目眩和想吐

He feels headache, nausea and vomiting.

他觉得头痛、恶心和想吐

His symptoms include loss of appetite, weight loss, excessive fatigue, fever and chills.

他的症状包括没有食欲、体重减轻、非常疲倦、发烧和发冷。