When your mind is agitated, your body starts to express it first.

Arjuna tells Krishna about what is happening to his body. He says that he feels a loss of strength in his limbs, his mouth is dry, his body trembles, and his hair stands on end. His suffering manifests not only as thoughts in his mind but also as clear physical reactions.

Young people, old people, relatives, and friends – the people in front of him are all heading towards death. He has come to terms with this reality all at once, and a deep fear and pity overwhelms him. Even as he tries to continue as a warrior, his body is already showing signs of its limits. This is a scene where the collapse within Arjuna becomes visible from the outside.

Japanese Translation from the Geeta Press Edition - Chapter 1, Section 28 (Second Half) to Section 29: "Disturbance Manifesting in the Body"

Arjuna said: Having seen this, my own people, Krishna, standing ready for battle, My body trembles, and my mouth becomes dry. And all over my body are goosebumps.

Vocabulary

"arjuna uvāca" means "Arjuna said."

dṛṣṭvā is "having seen".

"imām svājānam" means "these relatives."

"kṛṣṇa" is a vocative form, meaning "O Krishna."

yuyutsum samupasthitam means, "preparing to fight and forming a battle line."

"sīdanti mama gātrāṇi" means, "My hands and feet are losing strength."

mukhaṁ ca pariśuṣyati means, "My mouth becomes dry."

"vepathuḥ śarīre me" means, "A shiver runs through my body."

"romaharṣaḥ jāyate" means, "the hair stands on end," or "one's skin crawls."

Translation

Arjuna said.

"Krishna, Seeing these relatives who are arrayed for battle, my limbs lose their strength."

The mouth is dry, and a tremor runs through the body, the hair stands on end."

Annotated Translation

By these words, Arjuna is trying to show how terrible the consequences of indiscriminate killing in a large war are for both sides.

He knew that the young warriors and the old warriors, the close uncles, the cousins, relatives and friends, all were about to walk into the mouth of death.

By realizing this fact all at once, a sentimental feeling of pity arose in his heart.

A deep fear and pity arose in my heart.

And those things caused a reaction in the body, which manifested as trembling of the hands and feet, and goosebumps.